It is not known to evolve into or from any other Pokémon.
It is one of the Ultra Beasts and is known by the code name UB-05 Glutton (Japanese: ＵＢ０５ Ｇｌｕｔｔｏｎｙ).
Guzzlord is a massive, black Ultra Beast, being the heaviest of all Dark and Dragon-type Pokémon. Its main body is primarily spherical with a large, yellow mouth in the center. The top and bottom of the mouth are lined with two rows of teeth; the front row is yellow, while the rear row is black. In the second row of the upper jaw, two teeth curve out of the mouth similar to tusks. The inside of its mouth is a bright blue and its throat is lined with small spikes; its large black tongue is also lined with small spikes. Additional tongues resembling long arms with pincers protrude from its lower jaw even when its mouth is closed. Just above its mouth are two glowing, blue eyes with a yellow, diamond-shaped marking between them. Above each eye is a single, bat-like wing with yellow along the upper edge. There are other small bat-like wings down the sides of its body as well. On the underside of its body are three, fin-like projections that curve up towards its mouth.
Guzzlord's body is supported by a pair of thick legs, which have yellow zigzag markings across the knees and three claws each. On top of its body is a small, conical head with a second, smaller pair of glowing blue eyes. Four short horns with yellow tips form a ring around its head. On either side of its head is a larger, slightly curved horn also tipped in yellow. There is also a pair of arms on top of its body. Each arm has a hand with three yellow claws. A row of small spikes trails down its back and along its tail. The tail itself extends from the center of its back and resembles a medieval mace.
Guzzlord is said to feel like hard rubber. In order to eat, its tongue moves in a wave-like motion that pulls food towards its mouth. There have been reports of it eating mountains and buildings whole. According to Wicke of the Aether Foundation, its constant hunger causes it to eat anything within reach of its two, pincer-like tongues. Despite its appetite, no droppings have ever been found. It is speculated to convert everything it consumes into energy with no waste leftover.
Due to its habit of eating almost anything but not excreting anything out, Guzzlord may be based off a black hole, and also possibly a personification of gluttony. Additionally, it resembles a crab. The general shape is of an European dragon, while the spiny, mace-shaped tail is similar to prehistoric creatures such as the Ankylosaurus and Glyptodon.
Guzzlord may be a combination of guzzle (to eat or drink in a greedy manner) and lord.
Akuziking may be a combination of 悪食 akujiki (consumption of repulsive things), 悪 aku (evil), and king.