Big Octo

Whenever a creature becomes blocked by
Big Octo, tap that creature, it doesn't untap
during its controller's next untap step.
"If you see seagulls flying all around some sea
water, that's a sign that you need to be wary,
fry. Because the seagulls flock to wherever Big
Octos appear... BIG OCTOS, I tell you!"
—Fishman