Headbutt? In a moveset? Without Normal typing? Oh boy..
Headbutt is pretty strong even without STAB, but since Scraggy is so slow, it kinda sucks that the flinch chance is basically zero.
Drain Punch is my STAB of choice, as with a Big Root, Scraggy will not be going down anytime soon. It's a great move to use with Pokemon that how low HP stats like Scraggy.
Payback is also good STAB, as it makes use of Scraggy's low Speed. Added bonus for off-setting that Headbutt!
An elemental Punch (Fire/Ice/Thunderpunch) would definitely benefit Scraggy for the last slot. Fire Punch gets rid of Ferroseed, Ice Punch rids Dratini and Flying-types, and Thunderpunch can make sure Frillish is kept quiet. Dragon Dance could be a good boosting option, but you'd need a different Dark-type STAB. Fake Out is a no-fail, priority flincher, and is an amazing move to always have, especially on a LC star like Scraggy. Take your pick!