1. Cryodes have a Powerful Build (Large carrying capacity) and the Charger feat.
2. Once per long rest, as an action, Cryodes can shoot crystals out of their bodies, coating the ground in painful "caltrops." Everything within a 10-ft radius becomes difficult terrain, and causes 1d4 of damage whenever someone enters the space, or begins their turn standing within the circle.
2. Disadvantage on Dex skill checks and saves.
3. As an action, Cryodes can lose some of their larger boulders, decreasing their size, losing 2 strength, gaining 1 Dex (and I think you mentioned possibly losing disadvantage on Dex, but I dont know if we set that in writing).