Park Staff
- Badass Bookworm: He knows all about the prehistoric creatures he's about to face, and constantly tries to capture them. Most of the time, he succeeds.
- Expy: Think of this version of him as a time-traveling Steve Irwin.
- The Kirk: He's plenty snarky, though with a more jovial than sassing nature. He's also prone to emotional and logical choices in equal measure.
- Pragmatic Hero: In "Supercroc", he lures Matilda to the pond where the Deinosuchus he brought back earlier settled down, which snaps at her when she approaches; the situation was grave enough that even he was willing to take the very likely chance that Matilda would be eaten, or at least attacked.
- Butt-Monkey: He's usually on the receiving end of whatever bad things the prehistoric creatures brought to the park get up to, usually from the Titanosaurs.
- Cool Old Guy: Despite his streak of bad luck, he's a wise advisor to Nigel and knows when to take action when things go wrong.
- The McCoy: He's the most emotional of the main trio, especially when he has to deal with the animals Nigel keeps bringing back.
- Only Sane Man: He often complains to Nigel whenever he's planning to bring dangerous creatures back to the park, or points out the potential issues that may come with these actions. He's still fond of the creatures, even the Titanosaurs, but will still point out issues they cause.
- Hospital Hottie: Downplayed. She's a good-looking woman working as a veterinarian, but her attractiveness isn't put in any focus.
- The Spock: She's the calmest of the main trio, and the one who puts the most focus on her work.
- Team Mom: Especially in "Supercroc", where she had to nurse the new baby Sabretooths because their mother was unable to produce milk.
- Friend to All Living Things: Just as much as Nigel, and it's all the more heartbreaking to her when the pair couldn't save the Sabretooth cubs.
- Guest-Star Party Member: She joins Nigel's second trip to prehistoric South America to and save the last Sabretooth cats in the world.
- Panthera Awesome: She's an expert on big cats, having done field work with lions, leopards, and cheetahs in Kenya.
Animals
A teenage Triceratops that Nigel rescues from the mother Tyrannosaurus in "T-Rex Returns", becoming the park's very first animal.
- Demoted to Extra: Other than his introduction episode, he only has minor cameos.
- Pint-Sized Powerhouse: He starts out as a small dinosaur due to his young age, but he begins to grow rather quickly after his debut.
- Temper-Ceratops: A combination of territorial instincts and teenage hormones gives Theo an aggression problem. Bob deals with this by using tires and PVC tubing to disguise a tractor as another Triceratops, and uses it to stage fights with Theo so he can blow off steam in a controlled manner; becoming more prone to unleashing his fury on the vehicle instead of his fence and the parkkeepers.
- Artistic License – Paleontology: They're depicted as scaly and semiaquatic (to which Bob notes that they act more like ducks than ostriches), while the real ones were feathered and fully terrestrial.
A pair of young T. rex siblings that Nigel brings back from the Cretaceous moments after the KT asteroid collided with Earth, thanks to his ingeniuty and a ham sandwich. Originally brought back as juveniles, they mature rapidly and develop fierce tempers, making them difficult for the parkkeepers to handle.
- Artistic License – Paleontology: They're significantly more slender as adults than Tyrannosaurus was in real life, barely changing from their juvenile forms.
- A Day in the Limelight: Terrance gets a whole subplot to himself in "Bug House", revolving around his being seriously injured and put on Death's door after a vicious fight with his sister.
- Big Sister Bully: Matilda is established as one since the end of the first episode, domineering over Terrance and outright trying to kill him in "Bug House". Even the narrator takes the time to note how her hostility towards her brother only seems to grow.
- Butt-Monkey: Terrance is the biggest animalistic Butt-Monkey in the series, given how much abuse he takes from his sister, even nearly getting killed by her at one point.
- Cain and Abel: A fight between the pair in "Dinobirds" ends with them being forcibly separated and a divider built inside their enclosure for Terrance's safety. "Bug House" takes it even further when Matilda breaks through to Terrance's side and nearly kills him.
- Demoted to Extra: While Terrance shares focus with his sister in the first episode, the later focus chiefly on the more active and troublesome Matilda while regalating Terrance to the background.
- Jerkass: Matilda, as much as an animal can realistically be, given that she's far more ill-tempered and confrontational than her brother.
- Fluffy the Terrible: They're Tyrannosaurus rex, one of the most revered (and feared) dinosaurs in history, and Nigel decides to give them the names of... Terrance and Matilda.
- Sibling Rivalry: The pair constantly fight with one another, to the point that the park staff had to separate them so they wouldn't kill each other. This culminates in "Bug House", in which Matilda breaks into Terrance's half of the enclosure and grievously injures him in a fight.
- Teens Are Monsters: Taken very literally with Matilda, a raging teenage T. rex that tries to attack anyone or anything that crosses her path, including her own brother.
- Terrifying Tyrannosaur: Matilda grows up to be a nasty piece of work, attacking her brother in a dispute which leads to the siblings being separated for their own good. By the end of the series, she becomes the main antagonist after a frightened Titanosaur breaks through her enclosure, allowing her to go on a rampage through the park as the breakout occurs.
- Artistic License – Paleontology: Just like her children and other T.rexes in the show, she’s a lot more slender than the real thing.
- Handicapped Badass: Even after getting gored in the left thigh by a Triceratops, she still manages to hunt and kill an Ornithomimus (a species of dinosaur that usually runs too fast for even a healthy T.rex to catch) to feed to her chicks. When a rival male attacks Terrance and Matilda, the still-injured mother fights the male to the best of her ability, before he kills her by smashing her head into a rock.
- Mama Bear: She defends her young from a rival male despite being greatly injured, but the battle unfortunately costs her her life.
- Worf Had the Flu: She's killed by the rival male because the leg injury she already had rendered her weakened.
- A Day in the Limelight: Aside from her debut, "Supercroc" had her feeling isolated again after the herd's matriarch rejected her. During the breakout, she briefly go toe-to-toe with Matilda to save the resident baby of the herd, allowing her to regain her position among them.
- Gentle Giant: She's as sensitive and sweet-natured as a giant, hairy, elephant-like creature can get.
- Honorable Elephant: She's a Gentle Giant who stays very calm around the parkkeepers. When Nigel found her, she was seriously wounded by the hunters who killed her sister, but refused to leave the sister's body until Nigel gently coaxed her to follow him through the portal.
- Mama Bear: She's quite fond of the elephant herd's baby, even rushing to defend it from Matilda during the breakout.
- Too Unhappy to Be Hungry: After she's brought back to the park, Martha loses her appetite, putting her at the risk of her infection flaring up again. Nigel first assumes that she's being fed the wrong kind of plants, but it's only after he offers her some authentic Ice Age grass that he realizes she's a herd animal kept in solitary confinement, refusing to eat because of the loneliness. With Bob and Suzanne's help, he introduces her to the park's herd of African elephants, who accept her and allows her appetite to come back.
A giant, hairy, one-horned prehistoric rhinoceros encountered by Nigel when he travels to the Pleistocene for Martha's Ice Age grass samples. He decides to bring the beast back to the park as well as the grasses, since the approaching change in climate will render it extinct.
- Animal Stampede: During the breakout in "Supercroc", he's seen fleeing the approaching Matilda alongside the Ornithomimus flock.
- Toilet Humor: Though he's put on the sidelines after he's brought back to the park, "Supercroc" gives him a couple of cameo appearances. The first of these appearances has Bob looking after him while shovelling the many piles of dung he's produced, a sign that he's content in his new enclosure.
- Raptor Attack: Melanosomes found in the feathers of Microraptor fossils suggest it was completely black in color, instead of being largely white like the ones in the series.
- Gentle Giant: Despite their size and their tendency to destroy things, they're not dangerous. That changes in "Supercroc" when Bob, startled by the stowaway Troodon, nearly crashes his jeep into one of them, sending it on a frightened rampage where it breaks through several of the park's enclosures.
- The Millstone: Thanks to their size, strength, and obliviousness, they frequently cause destructive trouble for the park.
- Their first breakout in "Saving the Sabretooth" prevents Bob from hearing what size cage Nigel needs for the Terror Bird he intends to bring back.
- In "Bug House", one of them demolishes part of the titular building while it's under construction, setting Bob back on his schedule.
- In "Supercroc", another one knocks down the trees that Bob and the other keepers are planting as future food for them. A frightened one also causes the breakout near the end of the episode, though that can be seen as more of the stowaway Troodon's fault.
- Mundane Utility: In "Bug House", Bob entices one of them with gastrolithic stones so it can be used to tow Nigel's stalled jeep through the time portal. As the narrator says, who needs a tow truck when you have dinosaurs?
- No Name Given: The name of their species is never stated in series, since at the time the series aired, they were no known sauropods from their time and place. Since then, three species have been identified: Dongbeititan, Liaoningotitan, and Ruixinia (although none of these are true titanosaurs).
A giant, flightless, carnivorous bird, likely of the species Phorusrhacos, encountered by Nigel during his first trip to Pleistocene South America. Noting how its species was rendered extinct because they couldn't compete with the faster and more agile Sabretooths cats, Nigel uses a hunk of Toxodon meat to save it, tying the meat to his jeep and letting the bird charge after it through the time portal.
- Escape Artist: "Supercroc" shows that the bird has developed a habit of escaping its enclosure, since it's fond of taking dust baths close to the fence and digging holes big enough for it to slip through.
- Feathered Fiend: Subverted. It's a big and potentially dangerous predator, but its behavior is downright placid once it's taken to the park.
- Out of Focus: Though "Saving the Sabretooth" is promoted as being about Nigel saving both apex predators of prehistoric South America, the Terror Bird gets little screentime and is quickly caught early in the episode, while the rest of the episode focuses on Nigel and Saba-Douglas Hamiltong tracking down the last Sabretooths. It does get a bit more focus in "Supercroc", where it manages to escape its enclosure twice, first due to its habit of taking dust baths close to the fence, while the second time it escapes during the breakout.
- Big Creepy-Crawlies: All three of them look the part, as the Pulmonoscorpius is a feisty scorpion the size of a cat, the Meganeura is an active dragonfly with the wingspan of an eagle, and the Arthropleura is a millipede about two meters long, tall enough to look a man right in the eye when reared on its hind legs. Notably, the insectophobic Bob tells the viewers that he isn't frightened by these guys, espescially the Arthropleura, since they manage to win his sympathy because of their large sizes, making them appear as "proper animals" instead of tiny, wriggly insects.
A gigantic crocodile capable of hunting, killing, and eating dinosaurs. It's the last animal that Nigel (intentionally) brings back to the park, as he lures it out of the sea and corrals it into a makeshift pen so it wouldn't have anyplace to go but through the time portal.
- Artistic License – Paleontology: The one seen here is at least a third larger than the largest known real-life specimen, and it appears even bigger than that in the scene where it eats a Nyctosaurus.
- Never Smile at a Crocodile: Espescially a crocodile big enough to eat dinosaurs.
- Artistic License – Paleontology: The one seen here is depicted with a thin feathered coat, while the real animals are believed to have had a full covering of complex feathers.
- Hungry Menace: It's accidentally brought back to the park by stowing away on Nigel's jeep to eat his leftover Deinosuchus bait. After the breakout is fixed, Bob manages to trap it in its own enclosure by enticing it with more meat.
- Raptor Attack: Slit pupils, pronated hands, and a very thin coating of fuzz (making it look practically scaly).
- Unwitting Instigator of Doom: It's the reason the mass breakout happens, since it hid inside Nigel's jeep to eat the leftover meat he was using to bait the Deinosuchus. When Bob discovers it while driving the jeep, the resultant scuffle they get into makes him lose control of the vehicle and nearly crash into a Titanosaur. The startled sauropod promptly runs off and smashes open every exhibit it comes across, while the Troodon manages to slip away in the confusion. The end of the episode has Bob getting the last laugh by using more meat to trap it in a cage.