In the Feerrott (static zone): Known to spawn from PH "a frenzied Tae Ew" (roamer just around the edge of the wall around the corner from the spell vendors). He's also been known to spawn on the ramp. Note: For all named map points in Feerrott, the Dream, refer to this quest entry.
In the Feerrott (instanced zone): Spawns as part of the group mission "Fall of the Tae Ew".