Octocorns resemble seahorses. They can move at incredible speeds are seem to be addicted to cute things.
They were first seen in Water Baby. They were attracted to the sound of HJ5's music, and approached Lo Lo Sea Mall where they were doing a soundcheck. They would ram the dome, which eventually cracked and flooded the mall. While HJ5 managed to escaped, the Octocorns still followed them in their van. Love, using her language translator was able to decipher a message from them. It turns out they had a fascination with Baby's cuteness.
Baby became attached to them and told the other girls she wanted to stay underwater with her new friends. She suggested they keep them, but they wouldn't survive on land. They decide to erect a statue of Baby underwater so the Octocorns can remain happy and Baby can always visit them.