Planimals

Planimals are a common phenomenon where motile organisms are given the ability to photosynthesize. They usually come in two flavours: an already motile organism obtains the ability to photosynthesize (like via symbiosis with algae), or a photosynthetic organism is able to become motile. Based on the seriousous or the whimsiness of the game, one may not be acceptable.

Planimals who're derived from plant-like organisms are often seen in more whimsical games, due to their scientific implausibility, but there are exceptions, especially early on in games where the distinction of "plant-like" and "animal-like" organisms isn't super definied.