The named gorilla's (Silverflank Guardian and Hulking gorilla) drop clumps of gorilla hair. SO, hunting them for the rain caller's quest we discovered the Hulking Gorilla spawns quite fast after slaying the Silverflank Guardian. The first time the guardian showed up very quickly. The second spawn took over 2 hours. Not that bad actually.
Champion of Norrath
clumsy Taraya Radiance