As noted as a Shout-Out example, Zach's Zach-bots look a bit like Xiaolin Showdown Jackbots. Of course they do: the reason Zach's always trying to steal Aviva's inventions or roboticize animals with Creature Powers he wants to appropriate is that he doesn't have the imagination to come up with them himself. He got his "Zach-bot" idea from watching cartoons.
In the Thanksgiving episode, it's a Running Gag that Martin's Turkey Power Suit keeps losing its tailfeathers. Of course it does: rather than touching an actual wild turkey, he and Chris activate Turkey Powers using an already-shed tailfeather from a large wild tom. Whatever factors of genetics or physical structure had made the tom shed that particular feather, it carried over to all the tailfeathers of Martin's Power Suit! Therefore, they were so loose that even a collision with a tree or a tug by a baby raccoon was enough to uproot them.
In one episode, two lion cubs get covered in blue and green paint (which prompts Aviva to name them "Chris" and "Martin"). She does not show much concern that they where covered in paint, and they remain that way for most of the episode. The paint is most likely non-toxic, as many animals might be brought into the Tortuga and might get into them.
In "Flight of the Draco", Donita Donata uses a "Pose Beam" device to freeze Martin in place and manipulate him to walk a runway as her unwilling model. That in itself is pretty creepy when you think about it, but it gets worse. The scene cuts away for a minute after Martin is first caught in the beam, and then it reveals him in the outfit Donita plans to make him model. In other words, he was stripped while paralyzed. The fact that Donita seems a little too into him definitely doesn't help...
In "When Fish Fly", the gang were close to losing Koki for good, as she was lost in sea in her shrunken form and nearly drowned.
Then there's the Kratt Brothers having a brush with death or faced with an otherwise life-threatening situation nearly every episode. They almost died twice in "Whale of a Squid".
Zack's actions in "A Huge Orange Problem" are even more repugnant if you know much about wood types. Truly black (or "blackety-black") hardwood can be found in Africa, and near-black ones in Brazil, but the darkest species of ebony native to Indonesia is black with brown streaks. Had the Kratt gang not intervened, those Zachbots would have cut down every tree in Southeast Asia searching in vain for the right shade for Zack's table.
In one episode, Zack manages to hack Chris and Martin's power suits and force them to change into random animals at his whim. At least two of the transformations occurred in potentially lethal situations (a butterfly in a river and a fish in the middle of the African savanna) and while the rest weren't immediately dangerous, none of them were into animals suited for the environment so Zack very blatantly didn't care that he could have killed his rivals.
Any number of creatures such as Bitesize the little brown bat have made the Tortuga their temporary or permanent home. In "Puffin Rescue", we see how the five humans survived the turtle ship's swamping by a rogue wave, but there's no sign of any such resident animals' making a break for it in time. Plus, all that salt water probably killed the potted trees that the team members' sleeping hammocks are suspended from.
Paisley Paver's "pave over any and all natural areas" would effectively result in mass extinction of pretty much every living thing due to lack of oxygen and/or carbon dioxide poisoning, making her the most dangerous villain on the show to date.
In the Halloween special, Gourmand is shown capturing creepy animals in Africa, including a spotted hyena and a bat-eared fox. Later, when Gourmand demonstrates how he's hidden Goblin the Aye-Aye in a giant cupcake, the hyena is seen among the other crated animals, but the fox is missing. Still later, another two giant cupcakes appear to house Grabsy and Shadow, but the hyena never appears again. Nor are either of these mammals rescued by the Kratts. The logical conclusion? That the first giant cupcake Gourmand created was fox flavored and the second and third, hyena flavored.
At the end of "Adapto the Coyote", Adapto's seven younger siblings emerge from their mother's den and are ooo-ed and aaah-ed over by the team. Apparently, Adapto's Mom is fertile and competent enough to produce a litter of seven without difficulty ... and yet, Adapto himself seems to have no littermates. At least, no surviving littermates. Did Zack (who mentions having driven the coyotes away before) succeed in killing the other members of Mom's previous litter, leaving Adapto an only pup? For that matter, why isn't the father coyote helping raise the little ones?
