Dragging themselves about by their roots, the mobile Varga plants, half vegetable and half animal, had the ability to poison other creatures with their thorns, making them into other Varga plants.
Resembling catcti, the Varga plant thorn had venom. An infected victim would first grow homicical homicidal. As a second step, white hair would grow over their bodies.
Originally the Varga plants grew only on Skaro. (DW: Mission to the Unknown, BFD: Purity).
By the 39th century, the Daleks had imported them to other worlds, just as Kembel. The Daleks set up a base on the planet Kembel they brought some Varga plants with them to act as sentries in the jungle surrounding their base. They were suited to this as they could move around freely by dragging themselves along with their roots. Jeff Garvey and Gordon Lowery, members of Marc Cory's expedition team, got infected. (DW: Mission to the Unknown).