Potion

The potion is what turned Caroline and Clara into mermaids and David into a siren. It first appeared in "Magic Potion".

Description
The potion can turn a mortal into a mermaid and grant supernatural powers. When the sirens were created, they mixed the potions. So now, there's a 50/50 chance to turn into a mermaid or siren.

Full Moon
On a full moon, the potion fills back up.

Appearances

 * Magic Potion
 * Powers and Disasters
 * Troubled Waters
 * Crisis
 * Things Forgotten and Things Remembered