Red Lums resemble red, glowing orbs. In Rayman 2 they are similar to red versions of Yellow Lums, but look different in Rayman 3.
Red Lums are the manifestation of the Glade of Dreams' energy, and so without out them life could not exist. Though contradicting Rayman 2, the Heart of the World in Rayman 3 is confirmed to be made of Red Lums.
Red Lums are unique in that if spooked, a Red Lum will undergo a transformation into a Black Lum.
Role in the Games
Red Lums recover Rayman's HP. In Rayman 2, if Rayman is injured, nearby Red Lums automatically approach him. Robo-Pirates love Red Lums and collect every Red Lum they can find. By defeating a Robo-Pirate, Rayman can obtain all the Red Lums the Robo-Pirate found. Similarly, the defeat of a Hoodlum in Rayman 3 releases one or more Black Lums. If Rayman uses Grimace on a Black Lum, it will turn into a Red Lum.
In the PS version of Rayman 2, Admiral Razorbeard eats a Red Lum instead of a Yellow one.