I found a STL for using an AirTag to track your pet but it was in two pieces with tiny screws in it. I played around with it in Tinkercad and made about 6 test prints but ended up with a one piece print that I was able to work with.
I used the flexi TPA filament so I could squeeze the AirTag into the mount. I could have printed it at a hight density or with a smaller tip to get a smoother print but I was happy with my first successful mod. It worked well until our cat slipped out of the collar and it got hung up under some fallen timbers. To it’s credit, the air tag is still checking in months after it was lost.