Despite the ubiquitous presence of Poisons (my inner pedant nearly always perks up to mention that these are more accurately referred to as Venoms when it comes to monster attacks) I have never been terribly fond of just inflicting Hit Point Damage, a persistent (and often conveniently disremembered) penalty to rolls, or even that sainted staple of old-school play: Instant Death for these types of attacks.
Those may still occasionally appear as consequences, but I typically prefer these types of harm to linger a bit longer, create interesting challenges for the characters to overcome, and introduce another delicious layer of tension to the situation. For particularly dastardly critters, these sometimes can occur even on a “successful” Saving Throw.
I suppose some of the more physiologically improbable entries could serve as Calamitous Curses as well in a pinch, and I heartily encourage providing options for miraculous cures and treatments (driven by adventure generally of course). Perhaps some of these Herbs & Plants might be just what the Cunning Folk ordered?
So as promised during some of my d100 Encounter Activities, I went ahead and put together a table with One Hundred sometimes squicky ideas for giving these types of attacks a little more bite.
This table comes with a Content Warning for what I feel might qualify as mild Body Horror, because it is surprisingly tricky to explore these kinds of effects without a soupçon of the gruesome.