Sea unicorns are white with a light blue tail and a golden horn.
A sea unicorn appears on a wall hanger in "Bossy Boots" in Mr. Krabs' office, and when SpongeBob sings the song "Down the Well" in "Wishing You Well," he appears when SpongeBob says, "Although every day the pain grows, you'll ride unicorns on rainbows, if you throw all your dreams down the well." They are also seen in the background on the ball toss game in "Company Picnic." Pearl also draws a sea unicorn in the episode "Bulletin Board" and posts it on the Bulletin Board that was put up in the Krusty Krab.
Sea unicorns closely resemble seahorses.
In "Bossy Boots," Mr. Krabs has $20 sea unicorn wall hangers in his re-designed office.