- The Zach-Bots, especially when they take the form of a human.
- Many of the cruel things Zach does to the animals he captures, such as brainwashing walruses so they are forced to stay underwater until they drown just so they can find a pearl he stole.
- He's also unafraid to threaten his rivals directly as seen when he hacked their suits and made them transform randomly, with at least two transformations being directly lethal (a fish on dry land and a butterfly underwater).
- Gourmand's teeth gnashing in Stuck on Sharks. What made it even more creepy was he was talking to himself while he was doing it.
- Seven from Octopus Wildkratticus, post suit-tangling.
- Donita Donata paralyzes animals to make living jewelry out of, and even did it to Martin (to use as a model), on whom she seems to have a crush. There can be consequences to this: At least in humans, when the body is paralyzed with the brain intact (which is different from medical paralysis or coma), the victim usually strokes out within 3 months.
- Gourmand talks to himself in an unjustifiable way, sings jingles about eating endangered animals to himself; heck, the whole thing about cooking and eating endangered animals is creepy enough. Not to mention the fact that he's perfectly willing to cook and eat the Kratts if he can get his hands on them; the incident in the wild turkey episode could be more justified by the fact that Martin was in turkey form when Gourmand went after him but there is no excuse for wanting to make "a side of Kratt" out of a miniaturized Chris in "Platypus Cafe".
- The orcas fatally tearing apart a giant squid and eating it in This Orca likes Sharks deserves a mention.
Nightmare Fuel / Wild Kratts