10 Most Disturbing X-Men Villains

4. Master Mold (And The Sentinels)

Extraterrestrial threats and psychic demons might be terrifying, but you know what's scarier? Giant, genocidal robots.

The Sentinels have been a staple of the X-Men's comics pretty much since their debut, and have only grown more terrifying with every year. Readers have seen Bolivar Trask's cold, mutant-hunters ruthlessly murder dozens of mutants in the past, with arguably their most visceral kill arriving in the seminal Days of Future Past, when they disintegrate Wolverine into ash. Their gruesomeness is doubled in the film adaptation, where they brutally murder the surviving X-Men in all sorts of disturbing ways.

The Sentinels are a cruel reminder of humanity's capacity for evil (one that's reflected grimly in their anatomy), and while pretty much every Sentinel is scary in its own way, there is one that takes the cake - Master Mold.

Master Mold is a self-sufficient Sentinel who can create its own Sentinels. Also, it's bigger than all the other Sentinels and was once used in the aforementioned scheme by Cassandra Nova to wipe out all of Genosha, which resulted in the deaths of thousands of mutants.

Creepy killer robots are bad most of the time, but when they're also giant and can survive on their own? That thought is just straight up horrific.