Everyone knows about slimes and goo monsters. Some weird, melty, blobby thing that hangs out in dungeons, caves and the wilderness to make it hard for adventurers to get to the loot. Hard to take down with conventional weapons due to them not having much of a physical body and if they can resist magic, they're even harder. Ultimately, though, your average slime creature is easy to deal with if you don't let it catch you by surprise and you keep your head.
These are not your average slime monsters.
Unbeknownst to the larger world, these particular gooey creatures were made by a succubus centuries ago. Her goal had been to create some naughty little monsters that would be just as resistant to weapons as their normal counterparts but far more resistant to magic than the rare species and be able to wear adventurers out so she could take them all for herself. What she'd ended up making was precisely that, but with one small problem. She'd put a little too much of herself into their creation. Though they're not intelligent in the traditional sense, they're smart enough to adapt themselves to lure their chosen prey in and once they touch them, the aphrodisiac effect within their gooey form gets to work. Unfortunately for this succubus, who was never seen again, the slimes were not intelligent enough to recognize her as their creator. She ended up being the first victim of the slimes and is likely still paying for her mistake with whichever slimes that didn't migrate to another location.