A multipet, or multi-in-1 pet, is a pet with multiple options to raise within a single shell. Many bootleg pets like the infamous "Bunny Rom" have this model, but there are also many other pets that were advertised as such.
Bootlegs that use an existing intellectual property (like Pokemon or Hello Kitty) in the shell design to sell an item that is unlicensed will be shown in a different page.
Gameplay is unknown on most of these, and even pet lists are uncertain in many.
Most of these photos came from Tamenagerie.com, due to them being the only source that some of these even exist!
VR Lotsa Pets
8-in-1 Mini Pets -or- Octogotchi -or- Zoo Zone
3-in-1 Cool Pets
Electronic Pet Game
Z Pets 3-in-1
Seems to be an early Bunny Rom! Fewer pets than the Bunny Rom, but plays very similarly and has many of the same sprites.