This is a step-by-step guide on how to pet the Bunger.
How to Pet the Bunger
If the two Bungers are far away from each other, you may need to fire patches of ketchup on the ground to lure them to the same area. After this is done, fire some ketchup onto one of the Bungers. The other should notice and charge into it, stunning it in the process. You should be able to drop the Snak Trap next to it and catch it that way. You can also walk up to Bunger and catch it with the Bug Net.
After completing his quest, Gramble will set up his barn in Snaxburg. Outside of it is a donation box where you can drop off Bugsnax.
Walk up to the donation box and you should be prompted to donate your Bugsnax. Simply select Bunger and it should be donated to Gramble’s barn.
Congratulations! You are petting Bunger!