How does the spawn of Tremor Worm work and where can I find this boss?

Question

Killing this boss is required to obtain achievement Rumble in the Plant. Can somebody advise how does the spawn of Tremor Worm work and where can I find this boss? 

Answer 1

--EDITED--

He spawns during the Wild Life Raid in the Oramond Factory and teleports himself every 10 seconds around there. He drops Glooth Glider Crank which is needed for the Glooth Glider Mount.

About the spawn:
By voting at the Magistrate NPC you can manage to make the Wild Life Raid (or the other two) active. So once per hour (starting at SS) the Raid starts. The Tremor Worm spawns every time while the Wild Life Raid is active.

Comments

adds in his reply that: Every 10 seconds (approximate time) he may disappear and appear in another place in the room. It can also appear several times in a row in the same place.