What logical fallacy is someone using when they say "I hate blonde people because they're blonde."?

A logical fallacy is an error in reasoning that renders an argument invalid. acording to what i found. too me it sounds childish like if you ask a kid why they think a certain way and they don't know and are basing they're opinions off bias so they just respond with rather dumb answers that don't really explain anything. at least that's how I look at it, the only thing i could think of for his actual reasoning would be either he hates the way blond hair looks which seems kind of shallow to me, or based on stereotypes such as blonds being stupid or hateful.