Giant Squid (Phineas and Ferb)

The Giant Squid is a creature lurking in the ocean off Danville's coast. It attacked Phineas and Ferb's submarine and nearly ate Biff, but was stopped by Buford who subdued the creature with a single punch. ("Voyage to the Bottom of Buford")

Buford found himself in yet another tussle against this squid when he'd attempted to harvest seaweed from the ocean. ("Spa Day")