I know Xicotl and some of the other mobs in MM harm touch. If you want a list of mobs to check to see if you have as SKs, here's the mob hit point guide we used to use wayback (pun intended).
As far as Droga goes, the following are listed as SK. A goblin bodyguard (rare spawn), a goblin depredator, a goblin fanatic, a goblin mosstrooper and a golbin stalagknight. The last four appear to be very common with a lot of spawn points so if none of them are doing it now, that changes the dynamic of the zone quite a bit.
http://web.archive.org/web/200406110...cticiousname9/