Cerberus, Soul of Snow

When you cast Cerberus, Soul of Snow, pay {s}{s}{s}{s}{s} as an additional cost.
Cerberus, Soul of Snow is all colors.
At the beginning of your upkeep put a +1/+1 counter onto Cerberus, Soul of Snow.
Non-Snow creatures have -X/-X, X is equal to Cerberus, Soul of Snow's power.