A caveman, Spear, returns from spear-fishing to find his wife, son and daughter devoured by a trio of red horned Tyrannosaurus. Distraught, he contemplates suicide before resolving to take revenge. While fishing, he sees the silhouette of a dinosaur and, thinking it to be one of the Tyrannosaurus that killed his family, silently pursues it into a thicket. He comes face to face with the grayish-blue hornless Tyrannosaurus, Fang, with two offspring hiding behind her. The sight of the young dinosaurs momentarily causes Spear to back down, just as they are attacked by the red horned Tyrannosaurus pack. Though Spear helps Fang kill the trio, their gargantuan alpha arrives and consumes Fang's babies while Fang watches helplessly. Spear and Fang slay the alpha, but Fang is left distraught over the loss of her children. Spear leaves Fang and walks off alone, but is later approached by Fang, and the two decide to travel together.
Tropes featured in this episode include:
- Behemoth Battle: The fight between Fang and the horned Tyrannosaurus.
- Death of a Child: Spear's children get devoured along with his wife in the first episode. Fang's children don't fare much better.
- Despair Event Horizon: Spear's wife and two children are devoured by a group of tyrannosaurs. He climbs a large rock and stands at the edge, clearly about to commit suicide because he has lost everything. He manages to bounce back after seeing a vision of his wife and children in the rising sun, motivating him to continue living.
- Driven to Suicide: After losing his wife and kids to a pack of horned T. rex, Spear climbs a tall cliff and ponders whether or not he should just step off of it. He ultimately doesn't go through, but he did spend many hours at the edge of the cliff thinking if he should.
- Enemy Mine: Spear and Fang initially team up against the horned tyrannosaurs because Spear is seeking revenge for the death of his family while Fang is trying to defend her children.
- Evil Is Bigger: Fang, the sympathetic Tyrannosaurus, appears to be around 8 meters long, which is relatively small for her species. The antagonistic (although more "predatory" than "evil") horned tyrannosaurs are slightly bigger and their leader is humongous with a body length between 20 and 30 meters.
- Horns of Villainy: The Tyrannosaurus that kill Spear's family have Ceratosaurus-like horns, which the more sympathetic Tyrannosaurus Fang lacks.
- Informed Species: The Ceratosaurus-like theropods from the first episode are identified as T. rex by the animatic. Somewhat downplayed in that they do possess the general body size, proportions, and two-fingered hands of Tyrannosaurus.
- Interspecies Friendship: One develops by the end of the episode between Spear, a neanderthal-like caveman and Fang, a tyrannosaur.
- Licked by the Dog: After Spear and Fang defeat all the horned tyrannosaurs before the leader shows up, Fang's children are shown to be grateful to Spear for helping them and nuzzle with him briefly, like how a pair of puppies would. Spear seems to enjoy it too.
- Light Is Good: In a rather beautiful sequence Spear sees his wife and children in the rising sun, inspiring him to not commit suicide.
- Mama Bear: Fang fights tooth and claw to save her children. When both she and Spear ultimately fail, she launches herself at a monster ten times her size without hesitation.
- Mirror Character: Ultimately why Spear helps Fang. Just like him, she just wants to protect her children. Also just like him, she is ultimately unable to.
- Monster Is a Mommy: Spear thinks Fang is a predatory dinosaur similar to the ones that killed his family. Then he discovers she has two nestlings which she also tries to protect from predators.
- Monstrous Cannibalism: The horned tyrannosaurs are either the same species as Fang or a closely related species. This does not stop them from seeing Fang's offspring as prey. It should be noted that this isn't unusual behavior in the animal kingdom. It's fairly routine for large predators such as lions or bears to kill cubs that belong to other members of their own kind, both to better ensure the survival of their own progeny and to eliminate future competition over resources.
- Never Smile at a Crocodile: A gigantic crocodile, possibly a Deinosuchus, attacks Spear in the beginning of the episode.
- Only a Flesh Wound: Spear bashes one of the horned tyrannosaurs' legs in with a rock, resulting in a compound fracture, but after a few seconds of screaming it just snaps the leg back into place and keeps attacking like nothing happened, though it does seem to have a limp for the short period it survives after fixing its leg.
- Red and Black and Evil All Over: The horned tyrannosaurs that eat Spear's family and later Fang's are a dark shade of red with prominent black stripes. Of course, they're just predators targeting what they think are prey.
- Roaring Rampage of Revenge: After Spear's family is devoured by the horned tyrannosaurs, the caveman follows Fang with the intent to avenge their deaths (despite Fang not being involved in his family's death). Then the horned tyrannosaurs attack Fang and her offspring, and Spear joins the fight slaying two of the tyrannosaur.
- Shadow Discretion Shot: While the show seldom censors any violence, the horned tyrannosaurs eating Spear's wife and children is only shown in shadows.
- Sinister Silhouettes: When Spear first confronts the horned Tyrannosaurs, their gigantic Alpha calls them away before either side can decisively win. Said Alpha is only seen in silhouette in the nearby mists, but one can clearly tell it is far larger than the other three.
- Terror-dactyl: A gigantic pterosaur (called a "Pterodactyl" in the animatic) menaces Spear early in the episode, apparently smelling out the fish he carries. It can stand bipedally and is five-fingered (it has an additional thumb along with the wing finger and three small fingers).
- Vengeance Feels Empty: Judging from Spear and Fang's expressions after avenging their loved ones, killing the Horned Tyrannosaur didn't make them feel better.
- Your Size May Vary: Zigzagged with the Horned Tyrannosaur alpha: in the fight against Fang and Spear it is already much bigger than Fang, but seems to double in size offscreen as at the beginning of the fight its foot is only about as big as Fang's head, then later appears as big as Fang herself. Ironically, it seemed to be around the bigger size in its initial appearance at the beginning of the episode.
