The Tamagotchi species comes in a variety of different subspecies. each with their own unique characteristics that distinguish them from the standard Tamagotchi. However, they retain several key characteristics of Tamagotchi, such as the capability of Evolution.
Angels
Angels (てんしっち Tenshitchi) are a subspecies that acts as part of the Tamagotchi afterlife. Angels are born when a Tamagotchi dies, and their spirit, Obaketchi, evolves into Ghost Jr. They live in the Tenshitchi Capital, often have wings and/or a halo, and spend their time praying for the safety of the living Tamagotchis. They are sworn enemies with the Deviltchi.
Angels are raised on the Tamagotchi Angel. Names in English end in "Angel", with the exception of Ghost Jr. In Japanese, names end with "tenshi" (てんし) or "ten" (てん). "Tenshi" is the Japanese word for "Angel".
Deviltchi
Deviltchi (デビルっち Debirutchi) is a subspecies that acts as part of the Tamagotchi afterlife. Deviltchi are born when neglected Angels stray away from their angelic duties. Deviltchis only have four stages of life (three standard and one special), and can live for a lot longer than most subspecies. They live in the Devil World. Deviltchis usually either have pointed horns or black wings, although sometimes they can have both or neither. For an entertainment fix, Deviltchis like to spend their time bullying and harassing young Angels.
Deviltchi can be raised on the Debirutch no Tamagotch. Names in English will either end with "Deviltchi" (such as Girl Deviltchi), or have Devil in front of their name (such as Devil Mametchi). Names in Japanese will either end with debiru (デビル) or debirutchi (デビルっち), or have debiru within the name. "Debiru" is the Japanese word for "devil".
Mushitchi
Mushitchi (むしっち) is a subspecies that is comprised of bug-like Tamagotchi. The live primarily in the Mushitchi Forest (though can be found all over the planet) and are nearly invisible to the naked eye, which makes them vulnerable to being accidentally stepped on. Despite their small size and bug-like features, they are as sentient as a regular Tamagotchi.
Mushitchis are raised on the Mori de Hakken! Tamagotch and Game de Hakken!! Tamagotchi 2. The name comes from the Japanese word mushi (虫), which means insect.
Sakanatchi
Sakanatchi (さかなっち) is a subspecies that is comprised of fish-like Tamagotchi. They are born and raised in the Sakanatchi Sea, and can be found all over the planet. They are vulnerable to attacks from polar bears. Like the Mushitchi, they are as sentient as a normal Tamagotchi.
Sakanatchi are raised on the Tamagotchi Ocean and Game de Hakken!! Tamagotchi 2, and can also be observed in Hoshi de Hakken!! Tamagotchi. The name comes from the Japanese word sakana (魚), which means fish.
Ura Tamagotchi
Ura Tamagotchi (ウラたまごっち) is a subspecies of Tamagotchi that resemble normal Tamagotchis, except that they emit a light blue glow around them. They reside in Ura Tama Town, which is located inside the Tamagotchi Planet's mouth and it is therefore dark 24 hours a day. A large number of Ura Tamagotchis are opposite counterparts to regular Tamagotchis. For example, a lazy Tamagotchi, such as Kuchipatchi, will have an Ura counterpart that's more lively, such as Ura Kuchipatchi. A Tamagotchi can evolve into and out of the Ura subspecies (as demonstrated on the Tamagotchi Connection Version 4.5 and Tamagotchi iD L 15th Anniversary Version), and can breed with non-Ura Tamagotchis with no ill effect.
The standard Tamagotchi naming conventions apply to Ura Tamagotchis, however, if they are a counterpart of a normal Tamagotchi, they will have "Ura" (ウラ) in front of their name.
Gaiatchi
Gaiatchi (ガイアっち) refers to all living Tamagotchi that are part of the ecosystem. They have been visible since Tamagotchi was introduced, but the name for this subspecies wasn't mentioned until Tamagotchi 'Round The World. This term can refer to things like plants, trees, and clouds, but can also refer to Sunnytchi or even the Tamagotchi Planet itself.
Hanerutchi
Hanerutchi characters are characters based on characters and skits from the Japanese TV show "Haneru No Tobira". They reside in Hanerutchi Town. Hanerutchi characters resemble humans, although they still have "-tchi" on the end of their names and are capable of Evolution, whereas other human characters are not.
Hanerutchi characters are generally separated from standard Tamagotchis: They do not come into contact with each other although they have a similar lifestyle, except that their place of residence replaces all words and names of areas involving "Tamagotchi" with "Hanerutchi".
Hanerutchi characters are raised on the Hanerutchi 1 and Hanerutchi 2. The name "Hanerutchi" comes from Haneru No Tobira.