I am currently running a Kickstarter to fund a selection of multi-part floaty aliens - Overlords.
Most of the models come with as number of soft slots in which you attach a choice of tentacles. Being cast in resin, the tentacles can be easily manipulated when heated in water, allowing you to pose them as you see fit.
https://www.kickstarter.com/projects/1328919671/frills-and-fauna-overlords
Please feel free to check it out.
You can access previous Kickstarter items as add-ons if you missed out before!