Titan Mushrooms are a type of edible fungus originating on Titan. They were ingested for their psychedelic and hallucinogenic properties, and were known throughout the "space beatnik community" as Freaky Fungus.
On Red Dwarf
Approximately three weeks before the crew of Red Dwarf were killed by a radiation leak, Lister offered to cook Rimmer breakfast. He made him eggs, bacon, tomato, sausages, fried potatoes and a large quantity of mushrooms that he had stolen from the kitchens. Unbeknownst to either of them (according to Lister), the mushrooms were actually "Freaky Fungus" which probably belonged to one of the kitchen staff called Headbanger Harris. Lister however admitted to the captain that he'd done it "for a laugh".
After consuming the breakfast, Rimmer suffered a major hallucinogenic episode which he described as "a voyage to trip-out city". He first attended an inspection parade dressed only in a pair of mock leather driving gloves and some blue swimming goggles. He then attacked two of the ship's senior officers, believing them to be a couple of giraffes who were both armed and dangerous.
When he had recovered, he took Lister to see Captain Hollister and explained the inadvertent dosing. Lister did not want to get Harris into trouble, so he told Hollister that the mushrooms were his and that he had given them to Rimmer for fun. Hollister sentenced Lister to 2 weeks of Punishment Detail (PD), which Rimmer found unbelievable since the penalty for this crime was 15 years imprisonment. Rimmer became so angry that he was sentenced to 8 weeks of PD for sticking his pencil up Hollister's nose and eating a photograph of the Captain's wife.
Later, when Rimmer saw his future self's head emerge from the table in the sleeping quarters, he assumed that it was a mushroom flashback. Hollister did not help matters by attempting to apologise to Rimmer whilst the Captain was dressed as a chicken. Rimmer assaulted him and painted him green, then went to the medical unit. His stomach was pumped and his blood was changed to remove any trace of the fungus.
When the head reappeared later, Rimmer was determined to stay calm. This proved impossible when there were three versions of Lister, three versions of Rimmer, the Cat and Kochanski all talking at the same time. The original, human Rimmer screamed at them to go away and put the whole experience down to another hallucination. ("Stasis Leak")
- Given that it is a psychoactive mushroom, it is possibly a mutation or genetically-engineered version of "magic mushrooms", a real-life psychedelic drug on Earth.
- Since Titan Mushrooms are never actually seen on-screen, it is unknown what form, size and colour they took. However, given that Rimmer eats them without noticing any visual difference between them and common Earth mushrooms, they were certainly similar in appearance.
- The exact legal status of Titan Mushrooms in the Space Corps Directives is unknown; it appears as though they are illegal, since Rimmer accuses Lister of "smuggling" them aboard. However, Captain Hollister doesn't seem perturbed by the Titan Mushrooms themselves - as Rimmer notes, Lister got off lightly with only two weeks of Punishment Detail (Rimmer pushed for the penalty of such a crime be 15 years imprisonment, but Hollister says that two weeks PD is enough for what Lister has done). Hollister appears more perturbed by the continuing effects the drugs have on Rimmer's mind rather than the mushrooms themselves.
- Titan Mushrooms may or may not be similar to Space food.