Diet
It likes to eat many exotic and tasty dishes such as Oran Berry Fillet and Pecha Pot Pie.
Gender Diffrences
Females don't exist :3
Behavior
Likes to scare away innocent people and steal their Pokemon! Of course this is just a rumor spread by older brothers trying to scare their little sisters, and evil team rocket trying to make everyone distracted while they steal poor innocent pokemon, Thwomp Masters are quite nice, they love eating Spelon Berries.
Scratching
It likes to scratch it's back with Grip Claws. Of course this is just a rumor to scare Gligar away from evolving into Gliscor, as it is impossible for Thwomp Master to scratch it's back with a grip claw without it getting stuck in it's back.