It immediately headbutts anyone that makes eye contact with it. Its skull is massively thick.
(From Bulbapedia) Scraggy is a bipedal, lizard-like Pokémon. Its oval eyes are set to the sides of its head, and its teeth appear to be constantly exposed. There is a small red scale on its yellow head. Below the yellow portion of its head, its body is cream-colored with thin arms and a red, scaly belly. It carries its loose, yellow skin around its legs, resembling trousers, which garner them more respect the saggier they are. Some of the loose skin seems to trail off to form or cover a tail. This pelt is rubbery and can be raised to its neck in order to reduce the damage it takes from attacks. Scraggy is easily engaged in battle, as it will attack any foe that so much as meets its gaze with its thick cranium. Scraggy travel in small groups.
(From Bulbapedia) Scraggy appears to be based on a sort of lizard. In addition, with its moulted skin "pants", Scraggy seem to encapsulate stereotypes of youth subcultures of the past several decades, namely hip hop or punk.
(From Bulbapedia) Scraggy is literally thin/scrawny, but it may also be a combination of scrappy (referring to its tendency to fight) and saggy or baggy (in reference to its "pants"). It may also refer to scraggly (scruffy or unkempt).