Salamandra is a criminal organization lead by Azar Javed. The group is the primary antagonist of the Witcher game.
The organisation stole formula to make witchers to create own army of mutants. To have resources for experiments they worked as hired killers, drug dealers, robbers, weapon dealers, blackmailers and slavedrivers. Reverend (Witcher) aided them by selling them orphans. They kindapped villagers and forced them to take ingredients for drugs. They kindapped and bought children as test subjects.
Witcher Geralt found all their bases in Vizima and destroyed them with help of Triss Merigold, Declan Leavarden and troops of Siegfried or Yeavin. He discovers that Salamandra is in league with princess Adda. Geralt wiped whole organisation with Azar Javed in the end only to discover that behind Salamandra was someone with higher position.
The Witcher 2: Assassin of Kings
The Witcher 3: Wild Hunt