What is the oddest conlang you've encountered?
One of the coolest, strangest concepts is Rikchik, created by Denis Moskowitz. I did a whole write up on it here. It's a language created for green aliens with no mouth or ears, one big eye, and 49 tentacles. Seven of these tentacles are shorter and more agile, and so they're used for picking things up, and also for language. It's a sign language, then, but for use with beings that have at least seven tentacles. Here are some images of it in action:
I think it was brilliantly executed, and it totally defies what we usually think of as language. It's a true achievement in conlanging.













