Kalgruth, chaos ensuer

Trample

When Kalgruth, chaos ensuer enters the battlefield,
drink a beer.

Drink a beer—{1}{r/w}: roll a d20. If the result is major or equal than 16, target opponent's creature becomes an elf in addition to its other types until the end of turn. You may activate this ability only once each turn.

When there is an elf on the field, transform Kalgruth, chaos ensuer.