Since I got a lot of really positive reactions, I've decided to spend a bit of time cleaning up the project so that I could release it for everyone.
If you want your own LEGO/GoBrick mantis, head over to this GitHub repository. I've included all the files I created:

• The Brick Studio model
• The parts-list as .xml and .csv
• My custom instruction booklet, both for print and for digital use
• A pdf file to print the box
• A bunch of cool renders
• All source files for the above

The ReadMe file includes info on how to create your own kit and suggestions on where to order the parts.

The GitHub includes a 'Sponsor' button if you want to buy me a coffee to thank me for the effort

!! Be aware !!
The model looks really cool when built, but needs some support to keep its legs up: it is just too heavy for the joints of the legs to stay locked, and will not stay in position unless you very gently put it down. I'm sure someone with more LEGO skills can improve on the design!

Some of the images I posted on discord for the gift I made my buddy: