fraggle
noun
1
in prison, a mentally ill inmate. A Fraggle is a television puppet character from Jim Henson's Fraggle Rock, 1983–87; this excerpt from the theme lyric may well explain the derivation: 'Dance your cares away, / Worry's for another day [...] Let the Fraggles play'. Jim Henson also created The Muppets which also serve as models for the slow-witted UK, 1996.
2
(among Canadian Forces personnel) an avionics technician CANADA, 1995