Mandrels are a species of non-sapient bipedal beasts native to the jungle world named Eden. They appear to be an aggressive species and are usually seen in packs.
The Mandrels are squat creatures, roughly man-sized, with columnar legs and slashing claws at the tips of their hands. They are covered in dark purple fur on the head and shoulders, with purplish-red scales covering their abdomen and limbs. Their faces are dominated by a wide beaked mouth, the shape of which resembles a downwards-facing clam shell, with several thin short tendrils hanging from it. They also have a pair of large, menacing eyes which are pupil-less and light green in color. Their intelligence level is not clear, but it's possible that they might be comparable to Earth baboons, or perhaps gorillas.
The Mandrel body has been discovered to be a source of the highly addictive drug vraxoin. No other known sources of the drug exist, other than a species of fungus which has been eradicated from the galaxy. This might suggest that the Mandrels are fungoid creatures, perhaps related to the original vraxoin fungus. When a Mandrel is electrocuted, their bodies literally crumble to a pile of ash-like dust from which vraxoin can be extracted.
- Doctor Who season 17 (Fourth Doctor) – Nightmare of Eden (1979)
- They are not at-all related to the human character named Mandrel in the 15th season serial The Sun Makers.
- In the audio story Babblesphere (part of the Destiny of the Doctor series), the Eleventh Doctor lists Mandrels among his top five enemy races, along with Ice Warriors, Ood, Bandrils and Chumbleys. This is almost certainly a joke as, with possible exception of the Ice Warriors, all these can be considered relatively harmless compared to the average Doctor Who foe.