Gristleback

Bloodthirst is a static ability. “Bloodthirst N” means “If an opponent was dealt damage this turn, this permanent enters with N +1/+1 counters on it.”

“Bloodthirst X” is a special form of bloodthirst. “Bloodthirst X” means “This permanent enters with X +1/+1 counters on it, where X is the total damage your opponents have been dealt this turn.”

If an object has multiple instances of bloodthirst, each applies separately.