Thatch is the school bully at Capser's Scare School who is a vampire, mainly an antagonist in the film. He says he is, and seems to be popular, but a jerk instead, as he is conniving, selfish and mean. He is always looking for things to exploit and use to his advantage. His gang usually includes Slither, Dummy Girl, Mosshead and Harpy.
Thatch displays vampiric traits, mostly his ability to shapeshift into a bat. But oddly, he seems to have no aversion to sunlight as he has been in Deedstown several times during the day. He apparently has acid for tears as he once cried for not having the respect of his gang, his tears burning holes through his cape.
Although he's a bully, once in a while he finds common grounds with Casper and his friends, and even occasionally helps them, but goes right back to being the way he was before, as if nothing happened.