Frizard, Ice Lizard

A small lizard-like neutral mob. It has only two front legs which make it move rather slowly. Its body is grey with specks of white and on its back it has blue spines like ice. Frizards spawn only in biomes where it snows. The way they move is like that of a monitor lizard's form of running in that it sways its body from side to side. 

They are immune to powder snow's freezing damage and live in those blocks. They attack any mob that enters powder snow, and when it snows they will go wild and attack anything in sight. When outside of powder snow they are essentially passive and won't attack even if hit, instead opting to run away, basically the same way a croc would rather hunt in the water than on land. Being small, frizards aren't strong or durable, but attacking players in an already vulnerable state can make them a danger. 

On death they drop ice shards which can be crafted into an ice crystal. Ice crystals can be brewed into "freezing" potions which applies freezing damage. This way players can make freezing arrows or freezing splash/lingering potions. This allows players the ability to play around with an incredibly niche game mechanic without just having powder snow.