June 2018
Which (obviously SIMS) game are you asking about?
This forum is for the game "A Way Out".
June 2018
You can buy them through the computer when your vampire is lore level 3. You can also find them behind Vlads mansion (the largest in Forgotten Hollow).
After that you can plant them and grow them yourself.
If you want to read more about Vampires and Plasma fruit, check out this website: http://www.carls-sims-4-guide.com/gamepacks/vampires/becoming-a-vampire.php