Slinky Boy (or simply the 'little boy') is a perpetually lost little boy. He typically wonders if people are his dad’s mate, his father apparently going to Coburg for a meeting and never coming back. He also asks people where his lost Slinky is. He has met various people on his journey, including Ben (see Episode 1), a captain of a ship (see Episode 2) the explorer Robert O'Hara Burke of Burke and Wills fame (see Episode 3), stage actor Sir Robert Findlay, during rehearsals of 'The Blowout' (see Episode 6) and President Trump (see Episode 8).
In Episode 12 it is apparent that Slinky Boy has been living in the studio for the last 12 weeks and had written 'Ben is stupid' on the studio's whiteboard.
Slinky Boy appears briefly in Episode 25 at the bunker the Grub is broadcasting from, saying his dad has now gone to Queensland for a meeting.
The little boy returns in Episode 31 looking for his dad's mate. Guest of the show Henry Stone claims that he himself is the dad's mate and the dad is fine, which Stone triumphantly claims effectively 'kills' the character of the Slinky Boy. In reply, the little boy then asks for his Rubik's Cube and for the whereabouts of his mother who the boy says went to Fawkner.
During the Melbourne lockdown of 2020 the Slinky Boy met Greg and Ben again (see Episode 88). Slinky Boy revealed that he found his dad's brother (Uncle Stan) in Coburg whereupon he was told that his dad is now in Fawkner (seemingly mirroring the information about his mum). Later in that same episode Slinky Boy kicks a spoonbill which Greg describes as ‘cooked’.
Slinky Boy appears again in Episode 99 finding himself at GrubMart, repeating his story about his dad going to Fawkner. The boy apparently had been there for three days so Big Bill Simmons (the manager) gives him a job as a stockboy for 50 cents an hour which is likely to be only semi-legal.
Slinky Boy returns in his first live episode (Episode 101) albeit as a disembodied voice who claims he is both ‘everywhere and nowhere’. His Slinky is still lost but is later found under an audience member’s chair.