Thomas the Tank Engine.
Never realised as a kid, but now I'm a dad and I've had to sit through all the episodes, just about everyone is about a situation arising from Thomas being an entitled douchebag.
An ex made me watch the Gilmore Girls revival and I for the life of me could not figure out why Rory Gilmore was such a beloved character.
I don't know about beloved, but Greg Heffley was an idol in 1st-5th grade, who I realized in 6th how awful he is
Peter Pan. He was an absolute dick. He specifically targeted and tormented Captain Hook, who was a pretty tragic character in his own right.
Imagine - you're a middle aged, intelligent professor, and you suddenly find yourself in a strange world that is entirely populated by children and slow adults with the minds of children. All you want is adult conversation, normalcy; your old life back. And one child in particular has taken it upon themselves to gather up a gang, and to spend every waking hour coming up with ways to piss you off.
In the end of the book, Hook is practically driven insane by the constant harrassment. The whole scenario is practically a toned down 'Lord of the Flies' with a downtrodden adult thrown into the mix.
Grandpa Joe from Willy Wonka. This lazy fuck can't help out around the house and stays in his piss soaked bed for YEARS leaving poor Charlie's mom to do everything. Then the second Charlie comes home with the golden ticket, he gets up and DANCES A JIG! And then when they're at the factory, this miserable piece of human garbage convinces Charlie to steal fizzy lifting drink, and almost ruins his chance to inherit the factory. What a fuckface.