Narm: On the other extreme, some of the deaths can be seen as this. In particular was one episode where a man is killed by a hyena which contained Stock Sound Effects making it sound more like something out of a cartoon than a reenactment of a horrific death.
Nightmare Fuel: Some of the victim's deaths and their descriptions can be quite horrifying.
Some Anvils Need to Be Dropped: Wild animals can be very dangerous and should not be kept as pets. Likewise, even experts who are trained to handle dangerous animals can and do get hurt. Unfortunately, this aesop is lost in episodes where the show talks about a person getting mauled/killed by the featured animal for that episode when said person wasn't keeping the animal as a pet and was attacked in the wild. While it does show the animal is wild and dangerous, it's not the same as showing that the animal does not make a good pet.
The reenactment of Anita Finch's death. Between the music, the terrified resignation in her eyes, and the theory that she avoided seeking help out of a desire to protect her snakes (who were euthanized anyway), and it's very hard to watch.
The fact that many of the animals featured are killed just for following their natural instincts and being what they are. What's sadder is that most of them are killed to protect the public's safety and/or to save the life of someone they've attacked; these situations could have been avoided had the animals' owners actually shown responsibility and common sense.
Complete Monster: Continuing the tradition from his first appearance, Fabian Cortez is this. He's the mastermind of the horrifying hospice attack mentioned below, and also finds the time to infect Valerie Cooper with a mind-controlling Puppeteer Parasite before Exodus shows him to give him the thrashing he deserves.
Foe Yay: Professor X and Magneto have a moment where Mags cradles Xavier's chin and invites him to "walk down my path", proving that this trope is Older Than They Think in the X-universe.
Harsher in Hindsight: Professor Xavier mindwiping Magneto after he rips Wolverine's adamantium out, given that's the moment that'd give birth to Onslaught.
Moral Event Horizon: Magneto's interplanetary EMP strike doesn't have the emotional impact of some of his other crimes, but in terms of sheer numbers it might just be the most destructive thing he's ever done. Power was lost all around the world for hours, and while the death toll is estimated on-panel to be "hundreds, maybe thousands" the sheer logistics involved in such an event make the estimate seem ludicrously understated.
Nightmare Fuel: The Acolytes forcing their way into a hospice and brutally murdering the patients and staff.