The WildyWyrm is a boss variant of regular lava strykewyrms. They have a rare chance to spawn next to their lesser counterparts, and will then start roaming throughout the Wilderness, although in mound form. Like other wyrms, players initiate the fight by stepping on the mound, which will spawn the wyrm.
The WildyWyrm can also be summoned and controlled by Jagex Moderators, and they are capable of choosing their attack style and increasing their attack and defence levels. They can additionally heal the WildyWyrms in order to prolong the fight and create a greater challenge for the players involved.
They originally appeared as part of a small holiday event in 2011, possessing the same mechanics, although lava strykewyrms did not appear and they were instead found in one of three locations around the Wilderness, marked by some burnt trees (some of which still remain in-game). They returned alongside lava strykewyrms in 2015.