I've been wanting to make these for a very long time and they're finally here!

the holes are spaced 76MM center to center. It doesn't need supports, but you could consider adding a couple to the backside of the tentacle, Just make sure supports do not go into the screw holes.

Important:

You must add a pause in this print to add two 8-32 nuts. If you're printing at .2 layer height, that will be on layer 35, which is the topmost Layer of the cavity that you need to insert the nuts into before it starts to seal up.

I used these machine screws and nuts: Click here.