These lovely little “jellyfish” are made of airplants and sea urchin shells. I originally saw them at This is Why I’m Broke and assumed they came pre-assembled; however, the actual Etsy listing calls them a “kit” and specifies DIY assembly. If you’re gonna have to do that, you may as well just get the supplies yourself.
The plants appear to be one of the bajillion varieties of Tillandsia, which are widely available at nurseries and online (they even come in pretty colors.) If you want something a little more exotic, there are dozens of other varieties to choose from.
Sea urchin shells are similarly ubiquitous; you can find them at souvenir shops, craft supply stores, or online.
Stick the one into the other and you’ve got yourself a jellyfish. Hang with a bit of clear fishing line: You can drill holes in the shell if you’re feeling really ambitious, but it’s probably easiest to just thread the line through the hole and tie it around the base of the airplant. You can also hang several by repurposing a cheap photo mobile.
Plant care is minimal and easy. BHG has basic instructions.
These are a great decoration for an office or other area where there isn’t much natural light. They’d also make an interesting favor for an undersea-themed party or wedding.