Regigigas

Regigigas can't attack.
Whenever a Golem or an Elemental enters
the battlefield under your control, you may have Regigigas get +1/+1 until end of turn
or draw a card. When Regigigas gets +5/+5 this way, it and other Golems and Elementals you control can attack until end
of turn and must be blocked this turn if
able.