My very first sculpt I made about a month ago - made to the likes of Hercules' Hydra.
(Watch Video) If you have magnets (3mm diameter x 2mm thick) you can insert them in the slots I made for the heads to make it detachable. If not, you can just glue everything together.
You can file the male slots on the hydra_neck.stl if it doesn't fit the female slots.
Based on my experience printing this on ender 3 pro (FDM Printer), you would need to print the hydra_tail.stl flat (I already made it as such - so you can just print as-is). My attempt to print it standing resulted in a failed print.