To get this achievement more efficiently, attempt this on Easy difficulty.
Be a Herbivore and put Flagella, Jets, and Cilia instead of putting weapons on the cell.
Do not put the Jaw mouth, Spike, Poison, or Electric parts on the cell, they can harm and then kill any cell(s) nearby.
You can eat Junior eggs and still get this achievement.
Trivia[]
Despite it being a Cell Stage achievement, It says "without killing another creature". However, this is likely just due to it being a common cell reference.
