During the hiatus between the fourth and fifth seasons, Rose McGowan dyed her hair red to portray Ann-Margret in the biopic Elvis (2005). The writers explained the reason for the sudden hair color change by saying that Paige goofed up while making a potion and it caused her hair to turn red.
This marks the first episode produced by Alyssa Milano and Holly Marie Combs.
There is irony that Phoebe transforms into a mermaid, because it was Alyssa Milano's bright eyed character Samantha on Who's the Boss? (1984) that the title character of Disney's The Little Mermaid (1989) was based on.
Paige jokes about how long it would take in a salon to change her hair red. In real life, Rose McGowan spent 12 hours in a salon to change her hair style. It took two bottles of lightener, a bottle of bleach, and a box of red hair dye to bring her naturally dark locks to the red color we see in this episode and for the rest of the season.
This episode and "A Witch's Tail: Part 2" originally aired as a single 2-hour episode and without the usual opening credits sequence.