The Vrtra is an enemy from Crystal Defenders. The second major enemy encountered, the Nagaraja only comes in a wave of four, but their very high HP for this point of the game means a team might be unable to defeat a single one resulting in a loss of eight crystals due to their ability to steal two crystals instead of one. A large number of troops are needed in order to dispatch these resilient enemies, however, players can instead max out the level of some of their units.