Missy is Sissy's pink labradoodle, who is to Sissy what Dukey is to Johnny. Unlike Dukey, however, she is not modified in any way, and because of this she is unable to communicate through speech.
She only appears in Saturday Night's Alright for Johnny and Hoist the Johnny Roger She apparently has the ability to eat wood and barbed wire, and eats some boys that were guarding Johnny's house. Dukey also apparently has a love-hate relationship with her as Johnny does with Sissy. Later in the episode she farts very loudly.
Missy only appears in one episode and Sissy only appears without her from there on. She is voiced by Ashleigh Ball (who is also Sissy's voice actress) in Season 2-4, and 6 to present. During Ball's maternity leave, she was voiced by Maryke Hendrikse.