Question: What has eight legs and barks like a dog? Answer: Occy
The reason that wasn't funny is because it wasn't a joke. Nope. Occy, the pet of Snork Allstar Seaworthy, happens to fit that description exactly.
While tuna are considered the chicken of the sea, Occy, or more precisely, octopus canis, are more or less the dogs of the sea. As opposed to your typical ink-squirting octopuses, this little guy is a much smaller and friendlier species, known specifically for its loyalty, as well as the aforementioned barking.
They're relatively harmless, however some have been known to have a fondness for chasing tuna, or rather... Sea Chickens.