Greater Wyverns are a more powerful form of wyvern. Like their weaker counterparts they can poison party members and deal a lot of damage in melee combat. Though not technically immune to spells such as Web and Entangle Greater Wyverns are resistant to them just as they are to all spells. As part of the Tales of the Sword Coast expansion they are designed to be challenging even to high level party's. Greater Wyverns can be found exclusively in Durlag's Tower on the third level of the labyrinth in the bestiary. (See Durlag's Tower Walkthrough)