1. Install the Island Paradise expansion pack. Mermaids are only available in this expansion pack.
2. Create a new game in Island Paradise.
3. Select the Create a Sim option.
4. Click on the Mermaid icon in the Species section.
5. Customize your mermaid's appearance. You can choose their skin tone, hair color, eye color, and tail color.
6. Give your mermaid a name and personality.
7. Select the Mermaid trait. This trait gives mermaids the ability to swim, breathe underwater, and use special mermaid powers.
8. Choose your mermaid's lifetime wish.
9. Click on the Create Sim button.
10. Your mermaid is now ready to play!
Here are some additional tips for creating mermaids in Sims 3:
* You can only create mermaids in Island Paradise.
* Mermaids can only mate with other mermaids.
* Mermaid children will always be mermaids.
* Mermaids can learn new mermaid powers by reading books and practicing their skills.
* Mermaids can use their powers to help or hinder other Sims.
* Mermaids can live on land or in the ocean.
* Mermaids can befriend or enemies with other Sims, just like any other Sim.
Have fun creating your own mermaids in Sims 3!