For complete jellyfish, you will need one hat, one core element and 4-8 tentacles. While printing tentacles you can resize some of them in your slicer program for nicer result.
All parts except hat can be printed without support. For hat, I recommend to print it upside down, so the support material touch only the external hat surface and is reaches to a height of 15-20 mm.
If you make your own jellyfish with this project files please let me know by sharing some photos :)