Slolb, the Treacherous

Slolb, the Treacherous can't attack.
At the beginning of your upkeep, if an opponent controls the creature with the greatest power or
tied for the greatest power, that player gains
control of Slolb, the Treacherous.
{t}: Slolb, the Treacherous deals 1 damage to any
target except itself. Activate this ability only if
another creature you control is attacking.