Varimathras and other NPCs are not spawned pre-Battle for the Undercity bracket.

[heyitsbench]

Before the Battle for the Undercity was released, many NPCs were placed in the Undercity (such as Varimathras) or were in place of other mobs (like the Kor'kron Elites). These should be spawned in the brackets prior to the Battle for the Undercity quest is available.

Originally reported at chromiecraft/chromiecraft#5844.