In the current demo, Aychem can use the one HM unlocked by the gym: Cut. However, it has 5 alternate forms in total:Cut Aychem, Smash Aychem, Surf Aychem, Strength Aychem and Fly Aychem. Its typing changes too: Cut makes it an Electric/Grass type, Rock Smash makes it an Electric/Rock, Surf makes it an Electric/Water, Strength makes it an Electric/Fighting type, and Fly makes it an Electric/Flying type.
Pokédex entry
Pokédex entry
An artificial Pokémon designed to perform various functions. It can change its shape into different forms.