Numa Numa no Mi (KK21)

he Numa Numa no Mi is a Logia-type Devil Fruit that allows the user to become an element of "swamp" making the user a Swamp Human (沼人間 Numa Ningen?). "Numa" (沼) means "swamp" or "bog". In the Viz Manga and FUNimation subs, it is called the Swamp-Swamp Fruit. It was consumed by Caribou

Strengths and Weaknesses
With the Numa Numa no Mi, Caribou can create bottomless swamps which are impossible to escape from. If someone is caught by the swamp created by Caribou, they will sink more if they struggle. The swamp also serves as a storage space, allowing Caribou to store an infinite amount of whatever he has captured inside his body. He is able to keep creatures capable of breathing water, such as mermaids, alive while they are in his swamp. Whether he can keep creatures only capable of breathing air alive in his swamp is unknown.

Like most of the other Logia users, Caribou cannot be hit or sliced as his element is intangible, and any attacks will be absorbed into his body harmlessly, though more like Marshall D. Teach, Caribou cannot allow the attacks to phase through his body; instead, it must be absorbed. The thick liquid produced by the fruit's power is probably mud, which is found near marshes and bogs, and Franky did describe it as "mud-like".

The major weakness of this fruit is that the user cannot transform back to their normal form if they are confined in a space that their normal body can't fit in. Due to this weakness, Franky was able to capture and seal Caribou in a barrel easily. Other than that the user is affected by the standard Devil Fruit weaknesses.

Usage
With his Devil Fruit powers, Caribou can create bottomless swamps by turning his lower body into a swamp. Via this transformation, he can capture living beings like he did when he used his powers to capture some mermaids. His "bottomless" swamp can be used as a storage place for his captured mermaids or the treasure he took from Ryugu Palace. In fact, his fighting style lies in storing several weapons like Gatling guns and scythes inside his body.

Caribou can also use it to suffocate his opponents by encasing their head in a sphere of swamp. Like other Logia users, he can evade (or in his case, absorb) attacks by turning his body into the related element, in this case, swamp. However, his over-reliance on this defense, which he incorrectly believed to be invincible, led him to have little natural defensive power when his ability was dampened by attacks imbued with Busoshoku Haki.

By becoming a swamp (or rather, a puddle of mud), Caribou can extend parts of his body, such as his ear, for eavesdropping while hanging on the side of a building to avoid detection.

Attacks

 * Numa Numa no Gatling Gun (ヌマヌマの機関銃（ガトリングガン） Numa Numa no Gatoringu Gan?, literally meaning "Swamp Swamp Machine Gun") - A large gatling gun comes out of Caribou's "bottomless" swamp stomach and he shoots his opponents with it. It was first seen used against Pekoms. In the Viz Manga, this is called Swamp-Swamp Gatling Gun.