Unnamed in the show, but later named in a tumblr ask post by character designer Rae Gaiger, Leech first appears as a member of Admiral Scurvy's crew in "Boys' Night Out". Leech helps Scurvy kidnap Sea Hawk, Bow, and Swift Wind to turn them in to the Horde.
In "Perils of Peekablue", Leech sees Sea Hawk with Mermista at the soiree and almost blows their cover. He is subdued and tied up behind the bar with other people that have sworn revenge against Sea Hawk. Their relationship with him was not friendly, as Sea Hawk having implied that he set their ships on fire.