My kids have had fun with turtles, and I had printed the original of this design. Then I got an Airtag to help me not loose my keys... but didn't want to give up my turtle keychain... solution modify to make hold an Airtag.

This is a tight friction fit, with a satisfying pop when you push in the airtag. That being said getting the Airtag out is a bit hard, but there is an access hole to help. I don't expect to take out the Airtag till I have to change it's battery so I errored on the tight fit side.

Modified height of keychain to match enough of the Airtag curve. Also moved the keychain hole to the foot, so Airtag could take up most of the body. Also scaled, made as small as practical with keeping room for Airtag.

Printing:
Infill - default 15%
Material - PLA
Machine - Prusa Mini
Resolution 0.10 mm
Time - 1h 18m
Post print - none, just add to keys