Merriel-Marisol is an older sea otter from the Theta the Otter series and Theta's biological mother. She makes a brief appearance in the first book during a flashback, in which she makes an attempt to abandon Theta as an infant, calling him "cursed" due to his genetic mutation causing his pupils to glow. Since her husband Kasem disagrees with her and wants to take care of her son, she ditches the two of them, and is not seen again in the series so far.