No child wants to be told that he's a mistake, but that's exactly what the monster is. Yes, Dr. Frankenstein intended to create him on purpose, but definitely not with an "Abby Normal" brain. The doctor intended the monster to be given the brain of the saintly and brilliant scientist Hans Delbruck, but when Igor screws that up, the monster is brought to life with a rotten criminal brain, which causes some rotten behavior.
The monster's body is described as "Crude, yes. Primitive, yes. Perhaps even grotesque," so the abnormal brain doesn't help matters. He's prone to anger, doesn't know his own strength, and is scared of fire. Also, with all the monsters the villagers have seen over the decades, they don't take too kindly to this one. The odds are stacked against him from the beginning. Can you blame him for being a bit irritable?
It Isn't Easy Being Green
But there's a human nature down deep in there somewhere, probably as a result of Frederick's TLC and self-esteem building. He wants to play with a little girl but that doesn't end well (although not as badly as in the original version). And he befriends a lonely blind priest until the priest accidentally sets him on fire. He responds to beauty—specifically the violin music Frederick plays to lure him back to the castle.
We can't exactly say he's got rhythm, but he's willing and able to learn a song-and-dance routine (pretty exploitative if you ask us) for his big debut at the Bucharest Academy of Science. He's ready for his close-up until an exploded light bulb scares him and he freaks out. The audience starts to boo the performance. Stung by the bad reviews (and scared of the sparks), he attacks Frederick and the audience and runs off. But he's just misunderstood—is it his fault he got the wrong brain?—and the police haul him off to jail, poor guy.
So the doctor does something that we think many parents would do—he lures the monster back with music and gives the monster part of his brain in a transfer procedure. This enables the monster to talk as though he's educated. And, as Inga points out earlier, "his veins, his feet, his hands, his organs would all have to be increased in size. […] He would have an enormous schwanstucker." An enormous schwanstucker and a brain to go with it? Cosmo magazine might just declare this guy the perfect man. And he finds the perfect bride: Elizabeth, Frederick's former fiancée, who apparently has a thing for zipper-necks.
Happy ever after. As our grandmothers used to say, there's a lid for every pot.