Algae Unicorn

When Algae Unicorn enters the battlefield, lands
you control become 2/2 blue and green Weird
creatures until the end of your next turn. Then,
return up to one target creature you control its
owners hand.
Sacrifice Algae Unicorn: Lands you control gain
indestructible until end of turn.

Algae Unicorns are a docile species normally, but the streams around them are usually unsafe.