Now someone may have seen that Twitch clip of my samurai dying in parasite chambers.
If not, I’ll summarise: I was fighting this thing here.
Its typical behaviour is to have two Pterasites fly near it and drop bombs on the player, and it can also throw them itself. (That’s the important part.)
Some time ago Deca mentioned fixing invisible throwables from enemies, I think. But recently I noticed the above guy still occasionally throws invisible bombs, appearing on the player and doing a lot of damage, like just now on my new summoner and on my deceased samurai. So keep that in mind whenever you enter one hoping for some easy mana potions.