Zeb, the Muscle

When Zeb, the Muscle attacks, you may exert him.
If you do, tap target nonland permanent
an opponent controls. It doesn't untap as long as
Zeb, the Muscle is tapped. A permanent tapped
this way untaps when Zeb, the Muscle untaps.

As long as Zeb, the Muscle is untapped, other creatures you control have +0/+1.