Story of Delphinus

When he first saw Amphitrite, Poseidon wanted to marry her but Amphitrite preferred to stay single.  So she ran and hide in the Alantis Mountains.  Poseidon was persistent and sent the dolphin delphinus to find her.  Delphinus searched until he found Amphitrite among the islands.  Delphinus then persuaded her to marry Poseidon.  As a reward for his help Poseidon made Delphinus into one of the constellations.

Story of Scylla

Thought her husband was often unfaithful, like his brother Zeus, Amphitrite seemed to be a faithful and dutiful wife except one time.  She loathed Poseidon's infatuation with the sea nymph Scylla.  By throwing magical herbs into Scylla's bathing pool, Amphitrite changed her rival into a dog-like monster with twelve feet and six heads.  Each head had three rows of close-set teeth.  Her cry was a muted yelping. Scylla seized sailors and cracked their bones before slowly swallowing them.

Story of Theseus

Minos, King of Crete, did not believe Theseus when he said he was the son of Poseidon.  So Minos threw his signet ring overboard and challenged Theseus to dive in and find it. Not only did the hero retrieve the ring from the underwater palace into which it had fallen, but he was given a golden crown by Amphitrite.