Sims that are in the process of transforming into a Vampire or Mermaid cannot ask to turn or be offered to turn (Not changed) or be casted upon using the 3 spells (Addon Only).Īliens and Mermaids cannot become a Vampire without the Addon. Eating the Kelp and Going Into Water to be a Mermaid.The Sims 4 allows you to live out your wildest dreams. Here are all vampire cheats in The Sims 4. /img/1/0/0/3/4/3/4/1/MTS_TwelfthDoctor1-193-20_10-54-52AM.png The Sims 4 allows you to do a lot of things you can't do in real life, including becoming a vampire.