Within the series, he is a person who loves to party, like his fellow Olympian Gods. He also loves water, seeking out sources of water wherever he goes, an example being when he is seen hugging the Turner's toilet.
Poseidon is a tan muscular being with long, blonde flowing hair and a large beard. From his waist down, he has a fish tail instead of legs, meaning he is a merman. He is shown to be able to move on land by sliding along on his fish tail.