The list is not public
A player said they had every mutation except one rare mutation and the mythic, then asked for the rare names. The thread did not supply that list. Labels such as Gold or Rainbow from other Roblox games are not Evolve a Cell mutations.
Void
Another player said their mythic is called Void and that it upgrades movement so you teleport every 12 seconds instead of dashing. That is one description of one unlock. It is the only named mutation with an effect in the sources checked here.
If you have Void, test it somewhere safe and compare it with Space dash. The report says the teleport replaces the dash. If your own tooltip disagrees, follow the tooltip.
Unknown rares
Open Stats, unlock yellow entries, and read each mutation's text in game. Do not spend a currency this wiki has not seen named. When a rare name appears on your screen, that description is the fact this page is missing.
The Void entry repeats the same report in short form.