You ain’t lying. Especially for sir stubby legs! Fortunately, Grimgor is in the best stance for this attack and he’ll activate his cloister Enduring Shell to add his shield bonus to the save.
Ref vs DC21 - (1d20+10)[25] (Whew!)
Depending on results, I could advance and try to lock the beastie down. Or would folks prefer we let it advance closer to us?