Thank you for adding more stuff to PvM that actually requires you to use your head. In terms of mechanics glacors are quite well done. There are some issues they have however, which I'd like to adress in this topic.
It takes quite a long time to get to them, the entrance to their cave could be moved to shorten the distance. Or we could get a teleport to mudskipper point. It'd make them a lot more convenient to get to.
I personally don't really like that they're aggressive, but this isn't too much of a problem.
For a monster that requires your full attention, requires you to sidestep, you'll need to pray switch to kill and has more hp than most bosses its drop table is disappointing. Their numbers could definitely use some buffs if you want people to actually make them worth killing for their common drops alone. That is something you should go for on a monster with relatively difficult mechanics.
Also why do they drop bones? They're literally made of ice.
I think they should get a different slayer exp multiplier. They have more hp than kbd, gwd bosses, kq, sdc and chaos ele and more difficult mechanics than them. They require far more effort to kill, 5k a pop is a bit mediocre. Since they are available in larger numbers I don't think they should get the exact same multiplier as bosses, maybe one in between bosses and regular monsters. Perhaps this multiplier can be given to tormented demons as well, that would make them good slayer exp.
I also hope you plan on using the bane ore in the cave. There's a huge demand for bolts at the moment, bane bolts would be very useful.