Vraxoin

Vraxoin (also known as XYP or "vrax") was a dangerous addictive drug. Vraxoin was a grey, ash-like powder which could be ingested orally. The drug caused slightly drunken affects and apathy, then causes extreme anger during withdrawal. (DW: Nightmare of Eden) Vrax-users (also known as Vrax-Heads) were also known to become shaky and to lose both strength and concentration after taking the drug. (BNA: Mean Streets) The Fourth Doctor mentioned how it has caused mass chaos on several planets. (DW: Nightmare of Eden)

Vraxoin was made from a type of fungus, but the planet it was grown on was fire-bombed. It can also be harvested from the bodies of dead Mandrels, who disintegrated into Vraxoin if killed by electrocution. (DW: Nightmare of Eden)