Envenom Companion

You envenom your companion or eidolon's attacks, which drip with highly toxic venom for the spell's duration. The first time each round the target hits a creature with an unarmed Strike that deals piercing or slashing damage, that Strike deals an additional 1d8 poison damage. A creature that is damaged by this poison must attempt a Fortitude save. On a failure, it's also Clumsy 1 for 1 round. This spell can't target familiars.

Heightened (+3) The poison damage increases by 1d8 and the clumsy value imposed on a failed save increases by 1.