I don't know what it is,could be a sedum,rhipsalis or any number of plants,hard to tell.If i were you i'd put it outside,as it looks like it has been reaching for the light.Me personally i would cut that long piece into several pieces and try planting them,and still i'd move it outside where it get more light but not in direct sun.
HTH

I'm sure others will be along with some suggestions as well.
kathi

Not a Rhipsalis, but maybe a very, very etiolated Kalanchoe deprived of light. Maybe something like K. barbertonicus. Will never bloom in the winter without sufficient light.

I have no idea what it is. maybe a senecio, I think that there is a strange beauty to its unhappy condition. There is a guy on the forum called Caudex that could enshrine by staging it beautifully in one of his pots and then one could give it its own shelf on that wall and it would become art. It took 20 years to make that critter! and it is still growing for the light. Nothing but persistent,

I think that C & S shows should have a competition for the most artfully etiolated plant. It could be a form of plant art like bonzai. I am sorry that I am no help. I do find your plant amazing. We have been seeing on our forms lately, a bunch of etiolated (stretched out because of lack of light). Yours is the most extreme so far.