- Broken Aesop: Protip: If you want to deliver the message that humans are bad for the environment because they keep driving cool animals extinct, don't use a creature like the Haast's eagle that specifically preyed on humans as an example.
- Nightmare Fuel: In "The Eternal Frontier", a bunch of hunters come out of nowhere and kill the giant ground sloth.
- The short-faced bear chases an early American away from the dead mammoth and into the forest, where it kills him.
- The megalania in "The Burning", with its poisonous saliva. It is scary how the creature is built up throughout the episode (with its tracks, dung, and a diprotodon carcass) and when it kills two aborigines. Even its death is pretty horrifying, where the aborigines burn it alive.
- In "The End of Eden", a Haast eagle kills a moa and later two Maori women.
- Tear Jerker: The young daughter of an early American dies of a sickness in "The Eternal Frontier".
- Two aborigines are killed by a megalania and one is killed by a crocodile in "The Burning".
- Just the fact that all the animals in the show, both the herbivores and the carnivores, become extinct thanks to the humans.
YMMV / Monsters We Met