Characters you already weren't a fan of only to find out they're infinitely worse than you ever could've imagined

Sergey Taboritsky (TNO): Initially presents himself as a Russian Monarcho-Nazi, turns out he is in fact an insane conspiracy theorist who plans to burn Russia down in the name of a long dead king who he believes is still alive.

Mayor Jones (Scooby-Doo Mystery Incorporated): Already a pretty shitty and uncaring father to Fred, turns out he's not even Fred's father, he abducted him from his real parents in order to keep them ever coming back to Crystal Cove.

Pong Krell (Stars Wars: The Clone Wars): Presented as an anti-clone racist and terrible general, turns out he's he's a straight up traitor to the republic who tricked his troops into attacking each other.