I've never had one of these that lived, much less grew so long. Kinda looks like cereus or euphorbia but I'm not really sure. Can I propagate it? I see roots, but they're not where I would expect them so I'm hesitant to cut. Any suggestions? Thank you in advance!

That is a cactus, looks like an epiphyte (grows on top of other plants). Make your cuts at the narrow junctions in between sections, for the least exposed surface area. Leave the cutting for a week in the shade, then pot it up and start watering after another week or so. You could probably lay a segment on top of the soil if you wanted to experiment but I usually go for the vertical orientation to start (plant obviously sprawls wherever it wants).

Thanks Baja! I'll give that a try

I have never seen any cactus like this one before Ibis!! Amazing.

It reminds me of Pitaya or Dragonfruit cactus which is a hylocereus family. Check out this link:
Dragon Fruit (Hylocereus ocamponis)

It definitely looks like a cereus. Could be one of the night blooming varieties. This big guy is mine. Totally overgrown and in need of major division. They have a tendency to thrive on neglect in the tropics. Since you are in Orlando, you will have to protect it if you get frost. You can divide at the joints like Baja recommended. Best in a large container with a wooden post for climbing. It will get Big. Check out YouTube. There's some great videos on growing hylocereus or dragonfruit on there. Lots of ideas on how to pot it up and maintain its funky growth.

Thanks all!

@redsonja, I'll have to look it up on YouTube. I'd rather keep it in a natural state if I can. I hope it'll bloom sometime

Thanks Ibis. Here is what your division should look like. I inadvertently divided the monster in my backyard when I tripped over a terrestrial branch and nearly faceplanted into a palm. It already has some roots.