http://eqbeastiary.allakhazam.com/search.shtml?id=2341
and
http://eqbeastiary.allakhazam.com/search.shtml?id=2337
I went there in search of Red Hellebore, but neither of them had it. According to the rogue poison guide in the P99 Game Companion Jerris W'Selo is also supposed to carry "Silent Weapons of the Black Mask".
http://kikyara.tripod.com/books/books.html
&
http://kikyara.tripod.com/books/blackmask.html