Cryo was introduced in Borderlands The Pre Sequel.
Cryo Damage can cause the stackable Cryo Status Effect. Each Stack reduces the enemies movement speed until they freeze and are unable to move.
With a Cryo Efficancy of 100% enemies freez at around 20% of their health
Frozen enemies take 3x Melee damage.
Normal Mode: +20% Damage against Armored Targets. ±0% Damage against Flesh and - 30% against Shielded Targets.
True Vault Hunter Mode: +50% Damage against Armored Targets. ±0% Damage against Flesh and - 50% against Shielded Targets.