Sunken Ship

S1, E28: When Poppy and her friends decide they need gold for their statue they are building Cecil the Toad King, they go off in the submarine to the Sea of Shipwrecks to find a sunken ship with treasure. Seymour the Sucker Fish (Egbert) sticks to their sub, then promises to lead them to the ship, only to find the treasure chest guarded by a giant squid named Sophie. The chest turns out to be full of rubber ducks which float to the surface and Cecil and his Queen declare them more beautiful than gold.