Mega Abomasnow

Mega Abomasnow is introduced as the first Ice-type Mega Pokemon in Pokemon Go, and while not quite up to par with Mega Glalie, it's still a very solid Mega Evolution that has occasional niches over the competition thanks to its sub-Grass typing. With a DPS that's just a bit behind Galarian Darmanitan and a TDO that's fairly solid for an Ice Type, it's a solid choice overall that can definitely pull its own weight when fighting anything weak to Ice. However, when it's not somehow providing a benefit against select movesets, Mega Abomasnow's Grass sub-typing can also be a hinderance just as frequently. This is especially true against Flying Types or anything packing Fire Type coverage moves. It has a bit of DPS vs TDO competition with Mega Glalie, but in most cases which is best will come down to if Mega Abomasnow's Grass sub-typing helps or hurts it.

As for its performance as a Grass Type; it's one of the weaker Grass Type Mega Evolutions, but it's generally okay to bring along if you lack its competition.