Sheila and Sheldon are teal twin sibling possums (not to be confused with oppossums, which live in North America). The two can be told apart because Sheldon wears a fedora.
Sheila and Sheldon have a habit of stealing from other characters, mostly at night. They are also greedy and constantly try to get rich. Sheila has been known to date other characters so she could steal their possessions. She is also friends with Kuddly.
- Hairy - 1 ("Drought and About" along with Sheldon)
- Sheila - 1 ("Doom-a-rang" along with Platto)
- Hairy - 2 ("Doom-a-rang" along with Platto, "Drought and About" along with Sheila)
- Platto - 1 ("Doom-a-rang")
- Tiger Hunt: Sheila is either killed by snakes or falls to her death; Sheldon is smashed by two logs.
- Doom-a-rang: Sliced apart by boomerangs.
- I've Machine That Before - Bleed to death.
- Bunyip Alert - Killed by the bunyip.
- Photo Stop - Killed by attacks and paper cuts.
- Out of Outback - Killed by carnivorous fish.
- Outback Fire - Vaporized by Splendid and Glider.
- Drought and About - Drowned in flood.
- Cold Blooded - Killed offscreen by Dummy.
- Crime Does Pay - Ran over by Zet.
- Let's All Rebel Down - Sheldon is flattened by Sweeps; Sheila is shot to pieces by a gun.
- Tiger Hunt - Before death: Sheila is bitten by numerous poisonous snakes, while Sheldon slowly and painfully cuts off his trapped leg with a fork.
- Crime Does Pay - Both of them badly beaten by Zet.
- They are based on Lifty and Shifty, as both duos are greedy and love stealing.
- Sheila is slighty more competent than Sheldon.
- Sheila's name is Australian slang for "girl" or "woman".
- Like real possums, they are mostly active at night.
- Sheldon was the first AOF character to cry during their death, as in Tiger Hunt.