Bonk refers to a series of comic-style memes in which meme characters such as Doge and Cheems get hit on the head with bats, hammers and other heavy objects, accompanied by "Bonk" sound effect and clipart. The original image that spawned the meme depicts a Shiba Inu, named Copper.
Origin
On March 24th, 2016, Tumblr user didlo posted a photo of their Shiba Inu with the caption, "She ate a scorpion," depicting their dog named Copper with a swollen head and face from the sting.
Didlo later posted an update to their Tumblr, noting that Copper went to the vet after the incident, followed by more showing the dog had fully healed from the injury.