Tentacle Forest

When a massive amount of tentacle plants fsprout in a Demon Realm, they join together to form a Tentacle Forest.

Resume
A devilish forest crawling with ominous vine-shaped “tentacle plants” that exists on the outskirts of the demon realm. When they spot a female, regardless of her race, the tentacle plants of this forest will coil around her body, bind her in place, tease her, and penetrate every single orifice in order to suck out demonic energy. Since the tentacles know that a monster's demonic energy improves in taste and quality after she obtains spirit energy, if a monster brings her husband to visit, they'll coil around her and shower her with sticky juice that includes an aphrodisiac compound that makes monsters terribly aroused, then coil around her thighs and force her legs wide open, and face her in the man's direction, as if inviting him to hurry up and penetrate. Since the plants in the outskirts of the forest are comparatively docile, and disposed towards aiding them by making sex with their husband more exciting, many monsters bring their husbands with them when they visit to play. They enjoy the pleasure that using tentacles during sex with their husbands brings. But when a human woman who lacks the proper resistance enters the forest, the plants just keep totally violating her. She'll probably end up being transformed into a succubus or roper with nothing but thoughts of pleasure in her head by the time she emerges. Also the deeper into the forest one goes, the more ferocious the tentacles become. It is so extreme in the deepest parts that even a monster would hesitate to go there.

There are also plants that thanks to the huge demonic energy Demon Lord have even adopted the female form.