Really? Last time I played, I intentionally got hit by the tentacle plant, but it didn’t seem to do anything.
Is the iron maiden that thing you can donate blood to? or is it something else?
I know Iron maiden can make you pregnant but I've not tried with the tentacle plant and the mimic.
Tentacles work like other enemies such as goblins, pigman, etc2. You can use the cheat to see that at base, you have 10% pregnancy chance and can be increased with items or will be very high during ovulation.
Parasites like bees and snails always get you "pregnant", I think anyway. They even hijack your pregnancy and changes it to their own species. But I think the counter on parasite vs birth is still not on point?
I really like that at the current version, your baby will be more or less customised. The most unique one I've found is the Iron maiden baby. You'll have a flying mini iron head wrapped around by tentacle. I don't know how powerful it is compared to the others though.
This game has some really cool pregnancy mechanic overall. Parasites you gave birth to will still attack you while the "humanoid" ones will follow and protect you.