For the first generation on the Tamagotchi On, evolution is determined by both care and gender. However, from the second generation onward, the evolutions are determined by the genetics of the parents instead. See Tamagotchi On/M!xable Characters for what characters can be m!xed for each version.
Each version has the same teen and adult characters; baby and child characters vary between versions.
For first generation adults, conditions to obtain are based on care mistakes. However, some adults can be obtained a second way if they play with a toy or eat a food a certain number of times. Some adults need to obtain this second condition within a certain range of care mistakes while others don't have this restriction. Note that more than 6+ care mistakes will automatically lead to the worst care adults, even if the second condition is done.
Tama Pets are obtained by leaving an item in the backyard and checking outside until a Tama Pet comes to visit. The user will then have the option to adopt or send them away.
Leave Flying Disc, Binoculars, or Chick Nesting Doll outside. May come for other items, and may approach the current Tama Pet for breeding. Less common as a breeding partner than to appear for items.
Leave VR Set, Balloons, Racket, or Flower Cracker outside. May come for other items, and may approach the current Tama Pet for breeding. More uncommon than usual.
Leave Fortune, No G Kit, or Star Room outside. Very rare, and genes are more dominant.
Unnamed baby Tama Pet
Breed two Tama Pets. Shortly after hatching and prior to evolution, this is the form a baby Tama Pet takes. It cannot be directly raised, as it evolves right after the user's My Tama walks back outside to its attention call.
Leave Fly Carpet, Music Box, or Pastel Brush outside. May come for other items, and may approach your current Tama Pet for breeding. More common as a breeding partner than to appear for items. More uncommon than usual.
Sanrio Exclusive[]
Character
Artwork
Sprite
Obtaining
Unnamed
Leave Baku plush or XO Guitar outside.
Unnamed
Leave Gudetama Bacon or Trunk outside
Unnamed
Leave My Melody Car or Sky Crayons outside
Unnamed
Leave Cloud Maker or Twin Stars Slide outside
Unnamed
Leave Strawberry Tea Set or Strawberry Balloons outside
Fantasy and Wonder Garden Exclusive[]
Character
Artwork
Sprite
Obtaining
Unnamed
Leave Ball, Wonder Horn, or Wonder Bottle outside.