Gjalpinulva is the Mid dragon. You'll find her sitting placidly on a huge rock in her lair at all times except during a short period following 12:10 p.m. game time when she flies around the zone incinerating players on the ground with her flame breath. To escape this fate (her breath lands for thousands of hit points), when the /time gets close to 12:10 p.m., climb as high as you can on the walls to the west or east of the lair and wait for her to finish her flight.
The safest way to get to her lair is along the east and south zone walls. (I once made it all the way there with a solo runemaster.)
Gjalpinulva's trophy was one of the originals that were introduced into the game as part of the housing expansion on June 24, 2003. The mob itself was added to the game on February 7, 2002 when the epic zones went live.
This trophy is on display in house 42, Caerwent, on Gaheris.
Extra special super duper thanks to Ragniff of Gaheris.