Hpf... It's really easy
, first of all you have to kill his tamer and then just give him 3 steaks that you can find in near area - of course he got to eat them in front of you (but I think that if he eats them without you're presence that will be ok too) - >
[link] .
Hmpf... If you tame Snowflake you can get 2 achievements/ trophies (Skill to Survive and Father of the Year).