He is a stocky, beige fish-man with brown spots on his thick neck. He has pink trailings with yellow on the tips on his head and neck. He also appears to wear a white tank top and vertically striped pants. He also has a very large grin.
Kasagoba first appeared alongside Hammond and Hyouzou, riding on sea beasts right outside of Fish-Man Island. They intercepted the Straw Hat Pirates and gave the crew two choices; join the New Fish-Man Pirates or be crushed before being able to enter the island. After Luffy rejected the invitation, the Straw Hats used the their ship's Coup de Burst to launch themselves into the island. Kasagoba was surprised by the ship's unexpected maneuver. After wondering what to do next, they returned to the Fish-Man District to report to their captain.
Kasagoba, alongside Hammond and Hyouzou, later went to Mermaid Cove in another attempt to capture Luffy, but they were easily repelled. The attack knocked out Hammond and Kasagoba, but Hyouzou was able to block it and remained uninjured. After the Straw Hats left the cove, Hyouzou carried his two unconscious companions away.