I was fighting a momentus, and somehow it teleported me down to bedrock (y=2 or 3), in a space where i was literally suffocating inisde stone until I pulled out a pickaxe and dug myself out. Is this a normal part of the monster's coding? To add insult to injury, killing it only yielded 2 completely useless dragon stone fragments... Any chance we can get those turned off as a drop until they actually do something?
I'm not sure why you might have gotten teleported to bedrock; that certainly does not sound intended. However: Why? Isn't it better than nothing? Normally you'd get more rewards though, I'm pretty sure. I guess the algorithm detected that Momentus couldn't reach you, due to your being underground, perhaps? I think you just get unlucky, but if something like this happens again, be sure to report it with as much detail as possible, as maybe improvements to the Momentus code can be made.