Requested by @nohriangrimleal

Buizel is loosely based off of an otter, but isn’t really like any single animal in our world. It has several features that make it unique, and almost humanized: Buizel has an swim-tube-like organ around its neck which it can fill with air to float, and it swims by twisting its tails like a motorized propeller.

But not every aspect of Buizel is totally ridiculous: the air sac, for example, is a feature of a few aquatic mammals in our world. The walrus has an air sac that can hold up to 50 liters (13 gallons) of air to help it float:

The walruses’ air sacs are called pharyngeal pouches. A walrus has two of them, located on either side of their esophagus. Filling them with air allows them to float, often used to sleep in the water without worrying about breathing. They are also a vital part of the Walrus’ vocal system. When inflated, the air sacs create a large hollow space for their voice to echo off of, making their mating calls louder, more resonant, and therefore sexier to other walruses. When a walrus dives underwater, it deflates its air sacs just like Buizel.

Buizel’s propeller tail is a little more difficult to explain. Sea otters will often spin around while they’re swimming to trap and release air bubbles in their fur, which helps them swim better (see Wartortle for more detail). And yet, Buizel doesn’t spin around while swimming; only its tails.

Propellers create thrust because of the shape of their blades. The spinning motion creates a pressure difference on either side of the fan: high pressure on one side, low pressure on the other. The pressure difference effectively pushes the water to flow towards the low pressure, which in turn pushes the propeller (or Buizel) forward. Propellers are valid way to create motion, but its not seen at all in our animal kingdom. 

There are a lot of evolutionary reasons why animals don’t have propellers (many of the same reasons why there are no animals with wheels, either). Therefore, the closest thing to Buizel’s swimming in our world would probably be a single-celled organism using a flagellum. Flagellum are long tails which many bacteria, eukaryotes, archaea and sperm cells use to move and swim around.

Flagellum are run by little biological motors (as shown on the left). These motors create a free-rotating system capable of continuous motion without getting twisted up on itself. The motors operate using the flow of protons, which is one reason that a flagellum system would be impractical and impossible on macroscopic scales.

Buizel’s air sac is likely a pharyngeal pouch like a walrus has, used to help it float. Spinning its tails create a pressure difference in the water, which pushes Buizel forward while its swimming.

Pokemon ML AU, starring the Nino Squad. The Buizel Nino takes as the ‘good one’ but she causes trouble about as often as Raichu does. Raichu isn’t a total jerk, he’s actually a sweetheart and incredibly loyal, but that doesn’t mean he doesnt like to piss off other people. He and Plagg, Adrien’s Meowstic, get on pretty well. Two pets names Nino has for them are Rye-Bread and Little Lady, extending to a whole myrad of other affectionate things like, ‘Bubbles’ ‘DJ’ ‘Puff Neck’ and ‘Floaty’ for Buizel, and ‘Voltage’ ‘Ray Bands’ ‘Fight Club’ and ‘Little Bastard’ for Raichu

Nino has no idea how Raichu gets his sunglasses to stay in place. It confounds him every day. And he had bought the boom box as a joke, but now he can’t get Buizel away from it. She plays good music though so whatever.