Meglos is a xerophyte and the last of the Zolpha Thurans, a cactus like race of Zolpha Thura. Alongside the Daleks, Meglos is a favorite enemy of the Doctor and has faced against the Surgeon numerous times in literature
Meglos hired a group of Gaztak mercenaries, led by General Grugger and his aid, Brotadac, to bring him an Earthling. He was able to take on this human's form. Meglos then trapped the Fourth Doctor and Romana in a time loop before taking on the former's appearance. Disguised as the Doctor, Meglos had Grugger and his party take him to Tigella. He hoped to recover the Dodecahedron, a source of great power. Meglos shrank the Dodecahedron and then returned to Zolfa-Thura, where he began to activate it.
On Grugger's request, he planned to destroy Tigella with it. However, the Gaztaks turned against him and locked him up. He was forced out of his body and re-entered his cactus-like form. The Doctor had meanwhile reverted the calculations for the Dodecahedron, causing it to destroy Zolfa-Thura and Meglos.