Uploaded new models with more clearance if the carabiner is too difficult to open. There is also a model without the carabiner now. 

Here's the printing parameters i used but feel free to just use your own preferred settings. 

petg
3 perimeters
10-15% infill gyroid 
1.5mm layer height

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Keep your hands free when taking the dog for a wee, 
Oh no! the poop you suddenly need to scoop, 
The bag will now be a nag 
No trash bin in sight but you want to do it right
The bag must be disposed as it's supposed
But fear not! 
With this 3D print in your hands 
It will solve all the demand
You just put the knot into the slot
Attach it to the leash 
Your dog walk is now a breeze
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Prints well with both PLA and PETG.

The carabiner end twists open so you can attach it to your dog leash with no extra effort. 

sorry for the bad rhyme…