Malcar is an ancient alchemist.
Mumm-Ra summons Malcar, an ancient alchemist, to return from Tomb Town. The alchemist returns as he was when he died; old and weak. Malcar regains his powers after he visits the Canyon of Youth, and uses them against the Thundercats. He transforms all the Thundrillium on the planet into Thundrainium.
Mumm-Ra sent Malcar to the Canyon of Youth twice in order to restore his youth so that he could more effectively attack the ThunderCats. However, this plan backfires the second time as Mumm-Ra accidentally left Malcar in the Canyons of Youth making him revert into an infant due to Jaga's interference. With no memory of his previous life, the baby Malcar is given by Lion-O to be adopted by a Thunderian couple who arrived on New Thundera.