Pond Life is the fifth episode of The Worst Witch (2017 TV Series). It was first broadcast on CBBC and CBBC HD on 1 February 2017. It is preceded by New Girl and followed by The Great Wizard's Visit. The plot of the episode is loosely based on the book A Bad Spell For The Worst Witch.
Mildred and Enid have used a spell to make the ground springy like a trampoline, and are bouncing on it. Maud isn't impressed with them for breaking the rules. Mildred then receives a package from her Mum; it is her first toy, a teddy bear that sings 'One plus one makes two'. Enid thinks it's cute but annoying.
In class, Mildred is asked to demonstrate a transformation spell by turning a mouse into a frog, but she hits Ethel instead, turning her into a pig. Miss Hardbroom appears and orders Mildred to turn Ethel back, which Mildred does, but Ethel is stuck with a pig's nose. Miss Hardbroom tells Mildred that she will have to learn how to do a transformation spell properly or she will be leaving the school.
Mildred decides to run away, but Drusilla stops her and says that Maud and Enid are fighting. Mildred stashes her bag under a table, then follows Drusilla into a room where Ethel is waiting. Ethel turns Mildred into a frog, as payback for the pig nose, and throws her out the window.
In the school pond Mildred meets another frog, who says he was once a wizard named Algernon Rowan-Webb. Algernon was the first wizard to teach at Cackle's Academy, but only briefly, as he was turned into a frog and has been living in the pond ever since. Algernon shows Mildred a locket with a picture of a woman he once loved, and Mildred encourages him to come back to the Academy with her.Meanwhile, Maud and Enid think Mildred has run away, but then they find her bag under the table, and Maud works out what has happened, and goes to confront Ethel. Mildred and Algernon make it into the castle, and after nearly being caught by a cat, they are picked up by Miss Gullet and put into jars in the potions room.
The teachers are gathered in the room when Maud and Enid rush in with Ethel, saying that Ethel has changed Mildred into a frog. The frog Mildred starts croaking the 'One plus one makes two' song, and when Miss Gullet is about to put the frog in the cauldron, Enid grabs it and says that it's Mildred. Ethel is then made to turn Mildred back.
When Mildred says that the other frog is really a wizard, Miss Gullet grabs it and goes to put it in the cauldron, but Miss Bat vanishes the cauldron, saying that Mildred is telling the truth, and that the frog really is a wizard. Algernon is changed back, and it turns out that Miss Bat is the woman from the locket, and she's been waiting for him all these years.
It seems Miss Gullet turned Algernon into a frog so she could take his job, and she is dismissed from the staff as a result. Mildred, dreading Miss Hardbroom's test, goes to run away again, but Algernon encourages her try the test. He says he knows what it's like, being the odd one out, as the only wizard in a witch school. For the test, Miss Hardbroom produces a mouse and asks Mildred to turn it into a frog, like before. Mildred tries, but it doesn't turn into a frog; instead she rapidly changes it between other forms, such as a log, clog, bog and dog. Mildred is allowed to stay at the Academy and Algernon is re-instated in his teaching post.