Brother Hushmaster's Potent Asp-Spray
A powerful spell used in Sourcery by Marmaric Carding. The 8th-level Wizard had it ready (possibly stored on his staff?) during a meeting with Spelter just after Small Gods' Eve so as to not violate the truce (wizards see it as unlucky to fight another wizard that night). "Silver snakes" spewed from his fingertips, ready to kill Spelter, when it was met abruptly with Megrim's Accelerator. The reaction between spells created a ball of green fire and filled the room with fine yellow crystals.
Given the fact that Carding decided to use it, we can assume that it must be a very powerful spell. Brother Hushmaster appears to have not liked asps as much as Humptulip hated insects. Perhaps, if Hushmaster predated Humptulip, the Potent Asp-Spray is even included in Humptulip's Howe To Kille Insects?