Why does stewie griffin hate his mom?

Answer 1

The running gag of Stewie hating Lois has lessened over the seasons, but at the start of the series, he felt she stood in his way of world domination.

Stewie's obsession with matricide is only brought up briefly a few times in the series mainly because Stewie feels as if Lois has been impeding his plans for world domination.

Answer 2

No specific reason has ever been given. It was a running joke to start the series with and it was explained as simply his belief she was keeping him prisoner in her womb as well as her getting his way of taking over the world and the only way to stop her was to eliminate her.

However after his computer simulation where he thought he had killed Lois, he decided he wasn't yet ready to kill her or take over the world.

Answer 3

Stewie hates his mother because he wanted to go back in her womb and can't. And probably because she's too positive for her own good. That would kind of tick me off too.