One of the ancient wyverns who has taken abode in Archdragon Peak.
The Ancient Wyvern stands in the way of the route to the Dragon-Kin Mausoleum and the Nameless King.
This fight is optional.
Found in Archdragon Peak. The closest bonfire is Archdragon Peak.
Breathe Fire: shoots a stream of fire out in a massive cone, dealing constant damage.
Swipe: swipes at the player with it's claws.
Run through the ruined structure around to the scaffolding, then run along the scaffolding until you reach the ledge near to the wyvern's head.
Jump onto the wyvern head and plunging attack to instantly kill the beast. Be careful while jumping because missing will result in you falling to your death.
The safest way to time the jump is to wait until he finished his breathing attack and then run off the ledge (sprinting, but not jumping) and then to do the plunging attack
- This page is about the boss version. The non-boss Ancient Wyvern, encountered before the Great Belfry bonfire, can be found here.