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 17, target opponent's creature
becomes an elf in addition to its other types until the
end of turn. Activate this ability only once each turn.

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