Thunderroc is a bird boss. At the lowest Threat it has 930 health, hits for 21 and carries 0 armor; the uber version you meet in the Mortal Arena has ×1.6 the health and ×1.75 the damage. You need Thunderroc Pinion to call it out.

It waits at the end of Skyreach Bastion, in place of Imp Overlord, and belongs to Adventure Mode.

Every kill rolls its list 5 times. 8 Uniques sit on it: four ordinary ones splitting 90.0% of it between them, and four Exceptional ones splitting the last 10.0%, which puts any one of those at about 1 in 40 of what it gives up. The Exceptional ones are Fulgurite, The Stoop, Talonhook and Thunderroc's Halo.

It opens every fight with Talon Dive, then fights with Static Ring, Chain Arc and Static Charge. The cast bar under its health names each big move as it winds up, so a party can call them out to each other. At 60% health it changes phase with Dive Strafe into Skyfall. After each big set piece it stops for a breath: that is the opening to punish. At 15% it makes its Last Stand with Heavenfall, one named, fully telegraphed finisher, and no burst of damage skips it. The uber version in the Mortal Arena fights in three phases (Squall, Tempest and Eye of the Storm), grows between them, and adds Rolling Thunder and Twin Strafe. Its weak spot: Use the Rods. Stand by a lightning rod when it dives, then step aside: the storm earths through it.

It calls in Static Chick.