Captain Jetlag is a yellow silverfish that is dressed like a pirate. He has a grey beard, a wooden leg, an eye patch and a hook. He also has an anchor tattoo on his arm, which is a symbol of "sailing folk."
Captain Jetlag is a pirate Silverfish, his ship was swallowed by the Lungfish, which he believes is a "whale". Molly Coddle, Mr. Bumpy and Squishington meet the Captain inside the Lungfishes stomach where he first attacks them.
The Silverfish Pirate claims that the trio have come to ravage his vessel and demands to battle. The Pirate wants to fight them but he then accidentally punches himself in the face and blacks out.
The Captain wakes up facing the trio, Molly tells him that they are not pirates. Captain Jetlag still doesn't trust them, Molly tells Squish to show him his anchor tattoo (which is actually ironed on) and the Captain welcomes them, thinking to be sailor folk.
The Captain also appears to be delusional, believing that the Lungfish is a whale, Squishington tells him that it is a Lungfish, not a whale. The Captain learns this and mutters to himself no wonder he couldn't find the spout. When they are attacked by a giant Squid, the delusional Captain sees the Land Squid, believing that it's the great whale coming back to finish him off.
They began to set sail through the intestines, but got caught in it's digestive tracks. As Bumpy, Squishington and Molly got out of the Lungfish with a giant gum bubble, Captain Jetleg says farewell to his friends and he wants to go down with the ship.
Molly tells the Captain that "fool hearty bravado isn't necessary", Molly tells Bumpy not to take off yet but he accidentally drops the rope and it's too late. As they float away, the ship is destroyed and the Captain slowly goes down with the ship, where he is assumed to perish.
He was spat out at the end by the Lungfish when he was having a tongue blowing out standoff with Bumpy. The Captain is reunited with the group and is surprised that he is alive, Bumpy tells the Captain to "never underestimate the value of a good taunting". Bumpy then takes a deep breath and blows out his tongue, Molly, Squish and Captain Jetlag then join in and they all start blowing out their tongues together, ending the episode.