A good competitive cocancer set

[shademonkey]

But is there any move other than Rock tomb and stone edge? Rock tomb is weak and stone edge might miss in a tight position

Cocancer learns Rock Slide via TM. If you manage to outspeed the opponent you have a chance of flinching. 

I would strongly recommend against that, mate. Having two Pokémon on your team with a 4X Weakness to Ice is just begging for trouble, and M-Archilles doesn't like taking a STAB neutral hit regardless.

I was considering Cocancer for the overall bulk and Ground resistance, which appeared crucial to me in today's meta. The only Ice-move users I see played online are Electruxo, Fafninter and Syrentide, which is a lot less than the myriad of Earthquake users. A second double weakness to Ice moves (with Coatlith) is something I was prepared to deal with with the other mons on the team. But you're absolutely right to point that weakness, as while there may not be many Ice users at the moment (just my impression),Ice Beam remains very easy to splash on a team. I still have some thinking to do.