PlantSims can't be create through Create-A-Sim, but you may change your PlantSims appearence from the mirror.
PlantSims have the same life stages as normal Sims (only teens and older Sims can become PlantSims) but they don't have Hunger and Bladder motives.
Sims can become PlantSims by eating a Forbidden Fruit or take part in a science experiment at University (20% chance). Affected Sim will receive a "Botanitis Minorous" moodlet. If the moodlet is not cured within 4 hours, your Sim will become a PlantSim.
Getting Forbidden Fruit -- Search for seeds all over the town (including University neighbourhood). But it is really hard to find Unknown Rare/Unknown Special Seed.
Getting Forbidden Fruit -- PlantSims can't get pregnant or make normal female Sims pregnant (for male PlantSims). Successfully "Try for Baby" with PlantSims will result in having a Forbidden Fruit Seed in female Sims' inventory.
Getting Forbidden Fruit -- Transform any seed into a Forbidden Fruit Seed using the Gene Splicing Experiment This experiment don't always result in the forbidden fruit; however, Sims with level 3 and higher Science Skill have a better chance of success.
Getting Forbidden Fruit -- Obtained by using "Clone from Sample" (need level 9 Science skill). You can use either sample of Forbidden Fruit of PlantSims' DNA.
Forbidden Fruit -- Your Sims must have at least level 7 Gardening Skill in order to plant this fruit. It will take 4 days for the fruit to fully bloom. Forbidden Fruit plant must be harvested within a day or it will become barren.
Forbidden Fruit -- "Tend Garden" will harvest the fruit and store it in your Sims' inventory. A Forbidden Fruit plant only produces one fruit (or baby), and becomes barren after being harvested.
PlantSims Baby -- "Pick Forbidden Fruit" has a 50% chance of producing a PlantSim baby. The baby produced is a clone of the Sim who picks it.
PlantSims Baby -- Gender of your PlantSims baby will be random. Sims who pick the PlantSims baby will automatically adopt the child.
Special Abilities -- PlantSims can "Photosynthesize", which allows them to burrow under the ground to absorb energy and water. This action only available during daytime and lasts for an hour.
Special Abilities -- PlantSims are able to commune with plants which have reached their first sprout. PlantSims are also better gardeners than normal Sims.
Special Abilities -- Sims can ask PlantSims to give them herbs. If the request granted, the herbs will appear in your Sims' inventory.
Special Kisses -- PlantSims can give Flower Kiss to other Sims. Receiving Sims will get the "Obsessed" moodlet for 8 hours.
Special Kisses -- PlantSims can give their enemies a poisonous kiss. This interaction available under Specials > PlantSims > Poison Kiss. Receiving Sims will be plagued with a 3 hour long skin discoloration, and a "Poisoned" moodlet.
Cure -- There are a few ways to cure PlantSims. You can cure your Sims Botanitis Minorous at the Science Facility/College of Science for $3000 simoleon.
Cure -- Another option is by using "Super Spice" (can be created by do the "Herb Experiment" via the Science Research station).