Threefold Thunderhulk

Threefold Thunderhulk enters the battlefield with three +1/+1 counters on it.
Whenever Threefold Thunderhulk enters the battlefield or attacks, create a number of 1/1 colorless Gnome artifact creature tokens equal to its power.
{2}, Sacrifice another artifact: Put a +1/+1 counter on Threefold Thunderhulk.