Oh, absolutely! And Astarion's keeping quiet about it, because it's a baby mindflayer, and if it grows up, it kills him and then has a very good chance of killing a lot more. ...But he also wants to keep it alive, because it's given him the ability to walk in sunlight and resist the horribly abusive mental controls his vampire master put on him!

So his goal is to learn how to control it, which... That's pretty unlikely, but he's aiming for it anyway

This boy's a mess, let me tell you