Devil Creepers

A Devil Creeper's (previously call Hell-Plants) seeds are planted within a human host. When ready, the plant sprouts violently from their body, killing them in the process. The plants themselves are huge, covered in bulging eyeballs and fanged, lipless mouths.

In the RPG...

Devil Creepers are basically vegetable versions of a Xenomorph, though the seed is planted by a sorcerer instead of a Face Hugger. The seed will typically sprout in a week. It can be detected via medical imaging, though its successful removal is up to the Keeper's choosing—or presumably a Luck roll—with failure either killing the patient or inducing the Devil Creeper to sprout. Once free, the Devil Creeper roots to the spot the host's body fell, and cannot move from there, then spreading creepers and branches throughout its vicinity. 

    The Devil Creeper takes only minimum damage from non-impaling weapons, but normal damage from slashing/impaling weapons. Strangely, it is resistant to fire. 

    Many details have been changed for the 7e Malleus Monstrorum. For a start, the plant used to grow, gaining an average of 7 HP per round. Though SIZ wasn't listed, you can use the HP and CON to work out that it started at 50 SIZ and grew by 70 each round, which is insane. This has been completely removed now, and we are just given stats for an average specimen and a monstrous one. Another change is that when grabbed by a vine, a victim used to be drained of 5 STR each round. It was not explained anywhere why this was, and it has now been removed too, opting instead for simple crush damage. As for stats, CON used to start at 250, but is now a more reasonable 70 (though maybe a plant should be higher?). As mentioned above, SIZ was not given before, though could be calculated to be 50, whereas it's now 80. Its INT and POW have both been decreased, which I guess makes sense with it being a plant. STR and DEX remain unchanged.

In a video game...

I think Devil Creepers could work in a video game. I can imagine an NPC the player has come to know doesn't realise they have a seed within them, so when it sprouts, not only would the player have the shock of losing their colleague, but they would then also have to combat the Devil Creeper itself.

In a film...

I must be a sucker for man-eating plants, because I really like Triffids, and since reading up on Devil Creepers, I really like them now too, so I think they would be quite cool in a film. Having said that, such an antagonist probably would draw comparisons to the Xenomorph, so something unique would have to be done with it to alleviate that as much as possible.