Folly Calls is the third part of the 9th episode of season 4 in Dexter's Laboratory, which aired on September 12, 2003. In this episode, Dee Dee cuts off one of her pigtails and Dexter gives her a hair growth potion to get some of her hair back. However, Dee Dee uses too much of the hair potion, causing her hair to grow to immense sizes.
Dee Dee accidentally cuts off one of her ponytails and she gets Dexter to make a hair growth potion.
Dee Dee is up in her room brushing her hair so that it will be just perfect, then a hair sticks up and Dee Dee tries to comb it down but it is just no use. Then she gets out some scissors and tries to cut the hair off. When she does, she accidentally cuts off one of her ponytails as well. Dee Dee starts screaming and running around because of her messing up her hair. Then she has an idea to glue it back on, but it just slips right off.
Then, Dee Dee goes to see Dexter about it. When Dexter sees what she has done to her hair he starts insanely laughing at her. Dexter then refuses to help her with her problem and then Dee Dee threats to crush him like a bug if he doesn't help her. Dexter quickly gets to work making something to help her. He ends up making a hair growth tonic for her. He tells her to use one drop only.
Dee Dee goes into her room and uses the entire bottle on her hair which makes her hair grow extremely rapidly and it fills up the entire room. Dee Dee starts running back into Dexter's lab and whithout even looking at her, Dexter says that she used more than one drop. Dee Dee tells him that she did use one drop. She just used one really big drop.
Dexter tries to think of an invention to make her hair go back to normal size again. So, he goes to his Dad who is watching a commercial about hair transplants. Dexter takes Dad's hair which is really a wig revealing Dad to be bald and he scrapes some bald skin off of his scalp and runs off. Dexter uses Dad's bald skin to create a potion. Dexter gets into a machine that cuts through Dee Dee's hair and he uses the potion on Dee Dee to make her hair go back to normal again. Dee Dee yells at Dexter for using the potion in the first place and leaves. At the end of the episode, Dad finds the hair growth potion and uses it on himself.