Cloak and Dagger appear at the celebration of baby Melody's party, with Morgana riding them on her tentacles to get there. After her plan on threatening Melody was foiled, Morgana, along with Cloak, Dagger, and Undertow, now turned from shark to fish for trying to eat Melody, escape with Morgana swearing revenge. 12 years later, Cloak and Dagger appear at Morgana's hideout and snicker at Undertow's look after accidentally being turned into various ugly sea creatures by Morgana and then turned into a mini-fish again. Cloak, Dagger, and Undertow later take Melody to Morgana's hideout, where Morgana turns Melody into a mermaid and later tricks Melody into getting King Triton's trident for her. Later, Cloak and Dagger are ordered by Morgana to make sure nobody interferes with Melody's return with the trident. Unknown to them, on their way back, they are followed by Ariel and Flounder.
After getting the trident, Morgana imprisons Melody. When Prince Eric demands their release, Morgana has Cloak and Dagger drag him underwater with the intention to drown him. However, Sebastian pinches both their tails, causing them to let loose their captive, who is then rescued to shore by Ariel. The rays then drag Sebastian further down and getting him hit by an icicle but he ties their tails together, causing them both to get tied to the icicle instead. They do not appear after that, leaving their final fate, following the collapse of Morgana's ice fortress, unknown.
Cloak and Dagger cannot speak in the movie, though they do snicker, groan, and scream.
- The manta rays' names come from the term "cloak and dagger", which refers to any operation which involves stealth, subterfuge, espionage, or general sneakiness; all things which describe the rays' tasks to a tee.
- Although both manta rays look alike, it is unknown whether or not they are twin brothers.
- Cloak and Dagger both have large human-like teeth, while real-life manta rays have small pointed teeth for crunching oyster shells.