Availability: No more than 30 minutes between each repop.
The Tyrannosaurus Rex wasn't difficult at all with 3 heroes and archons - 2 archons could likely easily solo it.
Make sure you have a solid tank with good healers. The room appears to be low regen and, although the fight isn't hard or very long, try to conserve SP to heal if needed. The mob can be found in CPK, the NW spike of the Dinosaur area.
Tyrannosaurus Rex encounter
The Tyrannosaurus Rex will be found in CPK and it does aggro. Dispel haste, fireshield and sanctuary, and debuff as necessary. It didn't appear to be immune to any of the standard spells. The mob bite paralyzes, but is otherwise fairly straightforward as a boss. Does not cast.
Tyrannosaurus Rex carries:
Some divination items and, it appears, random scatters, and a throwing spear named 'a giant bloody tooth.' lvl 215.
Boss kill proven for : 240 - 241