original film series
Throughout the original film series, we see several of them appearing to the characters and singing.
A Nightmare on Elm Street (1984 film)
In A Nightmare on Elm Street, one group of Jump Rope Children appear in the garden of Springwood Senior High School and another group appears near 1428 Elm Street. All of them may possibly be some of his pre-death victims.
A Nightmare on Elm Street 2: Freddy's Revenge
A Nightmare on Elm Street 3: Dream Warriors to Freddy vs. Jason
From A Nightmare on Elm Street 3: Dream Warriors to Freddy vs. Jason there are six kids that have been shown. Three girls playing skipping rope, the two who move the rope sing the song. One other girl, watches them while clapping her own hands. There also sometimes appears to be two boys throwing a ball. The position is, the girls skipping rope in front, next to them there is a girl and beside her, two boys with a ball.
A Nightmare on Elm Street (2010 film)
In a dream, they appear inside the Dream World's version of Badham Preschool.