Glastrier, yet another slow bulky Ice type... though Glastrier is probably the one most capable of pulling off such a role. 100/130/110 defenses are phenomenal, leaving Glastrier with no cracks in its aegis unlike Avalugg and Cryogonal.... aside from being the poorest defensive Monotype in the game. 145 ATK and Moxie for an ability are nothing to joke about either, enabling Glastrier to snowball out of control. Or as out of control as a base 30 speed Pokémon can get.
Someone Get Me a Room for This Horse!
Glastrier
Item: Life Orb/Nevermelt Ice
-Icicle Crash
-High Horsepower/Bulldoze
-Close Combat/Megahorn/Throat Chop
-Protect/Taunt
Nature: Brave (+ATK, -SPE)
EVs: 252 HP/252 ATK/4 SDEF
IVs: 0 SPE
Glastrier and Trick Room go together like ice cubes and soda. Have Glastrier come in with Trick Room setup and wreak havoc as a super fast, super bulky force of descruction. Icicle Crash is the STAB of choice, being more reliable than Icicle Spear (which needs to hit 4 times to outdamage Icicle Crash), and not having negative priority unlike Avalanche. High Horsepower is generally the Ground move of choice, hitting Steel and Fire types hard, though Bulldoze is a AoE ground attack that can provide Speed Control in the event that Trick Room goes down/gets disrupted. As for the final coverage move, Close Combat is generally preferred, hitting opposing Ice types, non-Ground weak Steels (Ferrothorn, Levitate Bronzong), Rock types, and a myriad of other types, though Megahorn and Throat Chop hit Psychic types (aside from Gardevoir, Hatterene, and Tapu Lele) as well as picking up Dark and Ghost types respectively. Final move is up to preference. Protect is the requisite Doubles move, while Taunt provides valuable utility after Trick Room has been set up.
Other Options
Snarl/Icy Wind -Glastrier nearly gets the full set for stat dropping moves. However, Snarl and Icy Wind run off of Glastrier's mediocre special stat, so you would only be running them for utility and Glastrier is only fast in Trick Room, lessening the effectiveness of these moves. Doubles Only
Heavy Slam -Clocking it at 1763.7lbs hits most of the game for max power (anything at or lighter than 352.7 lbs) or at still a respectable base 100 power (up to 440.9 lb targets). This will hit every Fairy not named Xerneas in the game for max damage. However, many Rock types that Glastrier would love to hit with this move are too heavy for the range I just described.
Iron Defense/Body Press -Kommo-o proved how devastating this combination can be. However, Glastrier, while having fantastic DEF, does not get STAB, has a much worse defensive typing and its ability does not cause Body Press to snowball. Singles Only