Krashen, Ruler of the Skies

flying, double strike, hexproof, trample, infect.
Whenever this card deals damage to a creature, that creature's owner loses 1 life for every 5 damage dealt this way
{10}{t} This creature gains lifelink and indestructibility
{4}{u} This creature gains deathtouch and
When this creature leaves the battlefield, target opponent loses 25 life and sacrifices 3 permanents