The person who is DMing our Tyranny of Dragons campaign (HotDQ->RoT) is considering allowing my evil character to track down a Wyvern nest and find an egg to obtain a tamed mount using a significant chunk of my accumulated downtime. I made the case that this was fair, because in exchange I'm giving up a scarce resource that potentially allows you to craft powerful magic items (downtime days). Thanks to the DMG that just came out, there are now more extensive poison rules detailing the effects of Wyvern poison applied to a weapon and which may even allow me to harvest said poison from my mount.
The problem is, as written, the rules require the poisonous creature in question (in this case, my potential future Wyvern) to be either dead or incapacitated for up to six minutes as per DMG 258. I would like to be able to harvest poison without harming the creature (i.e., without doing any damage to it). Can this be accomplished? I am playing a Dragonborn Warlock with the Fiend patron and the Blade pact. Is there a Warlock spell capable of harmlessly incapacitating a target? I'm pretty sure Incapacitated is a very distinct condition, so not necessarily the same as Charmed or Paralyzed; therefore I'm unsure if Charm Monster or Hold Monster and their ilk are sufficient.