Ectoplasm
I once had opportunity to visit a strange old lady who swore blind she could nasally extrude ectoplasm. She’d sit there, in the dark, rocking gently, and then whoop loudly, causing me to leap in the air.
Invisible to all eyes except hers, a languid ectoplasmic tentacle would peer from her snout and poke around the room, examining all those present.
I always found the practice disgusting, preferring to keep a handkerchief in reserve for such moments.