Fenrir in Chains

Fenrir in Chains cannot attack or block.
Whenever another creature you control attacks
put a +1/+1 counter on Fenrir in Chains. At the
beginning of the next end step, if Fenrir in
Chains has 10 or more +1/+1 counters on it,
transform it.
"In chains, the wolf of Ragnarok waits, to seek his
revenge on those that betrayed him." - Tyr