Sludge Bomb was for Crobat, to replace Air Cutter :D
I almost forgot about Hidden Power. It turns out it's a Fighting type, so yup, it was a good choice. I guess I'll keep it with HP and then try and add something to take out Swagger for Iron Tail when I get Waterfall.
I think you should give it to Mightyena, it already has bad moves, Crobat has two types of moves, while Mightyena has dark and normal which isn't super effective against anything, take down also gives recoil damage, swagger isn't necessary in my opinion. Sludge bomb is in Dewford town (In the house where they talk about hip words) North of the Pokemon Centre, talk to the guy in white with glasses near the entry.
I switched out Air Cutter for Sludge Bomb and Bite for Shadow Ball, since I already got types covered on Mightyena. Just for curiosity's sake I put HP on Crobat and it was a Flying type.
Thanks to the both of you for the help =)