I noticed that Salamence learns fly after evolving from a shelgon and i wanted to know if any other pokemon besides salamence can learn an HM by leveling up
Really, use Google before you ask questions like this; i found this page in less that 5 minutes.
Wailmer and Shellder also learn whirlpool by level up in HG/SS
And volbeat learns flash
Hope i helped, a up vote and best answer would be very much appreciated ;D
Shellder and Wailmer can learn Whirlpool (Along with various others in HG/SS) Seaking learns Waterfall, and Volbeat apparently learns one I don't know of.