Hatterene is a small humanoid Pokémon with a thin, white body. Its head is round, has a small mouth, narrow black eyes with white pupils, and two elliptical, pink markings over each of its eyes resembling eyelashes. It also has extremely long, layered, symmetrical hair, far longer than its body is tall; much like a cloak, the hair on its head drapes to the ground and swathes around it to conceal much of its true body, which is adorned by a pink semitranslucent dress that gives it a much taller silhouette, resembling that of a stereotypical sorceress or witch. This hair is colored in a gradient of pastel-blue, pink, and white from its upper portions downwards. The hair above Hatterene's head is shaped like a wide-brimmed witch's hat with a conical shape serving as the crown of the hat formation. Extending from the pointed end of the hat is a single tentacle that ends in a pink bulb and a consecutive pastel-blue bulb that has a trio of sharp claws, which can articulate in a manner similar to fingers, jutting out of it. Hatterene is a female-only species.

Hatterene has a solitary and reclusive nature, emitting psychic powers strong enough to cause headaches as a method to deter others from approaching and disturbing it. It has also been observed that it dislikes loud noises, tearing apart perpetrators with the claws on its tentacle as a result. Due to its long hair obstructing its floating body, Hatterene's main forms of locomotion are levitation and short-distance teleportation. This Pokémon is also known as the Forest Witch.

Thanks to powerful Dynamax energy that allowed it to assume a Gigantamax form, Gigantamax Hatterene has grown to a colossal size. While its physiology remains vastly the same, its black eyes are now blue with white pupils. In addition to this, its hair has grown and increased in volume, forming a chamber of sorts that its body sits in. On both sides of this chamber are a pair of teardrop-shaped openings. The hat-like formation on its head has also changed, with the brim being thinner and draping around it and the crown ending in a pink bulb. Attached to the said bulb is a larger pastel-blue bulb that has three, long tentacles tapering from it. As seen with all Dynamax and Gigantamax Pokémon, three red clouds loom and swirl above the hat of Gigantamax Hatterene.

Known as the Raging Goddess, Gigantamax Hatterene has the ability to sense the emotions of creatures from over 30 miles away, and it will become enraged and attack if it senses any hostility. Its tentacles are capable of firing off energy beams akin to lightning.

Hatterene is the only known Pokémon capable of using the move Magic Powder and the exclusive G-Max Move G-Max Smite.