Dog King was born to the same father as Wu Song. However, through an unknown sequence of events, he came to be lost. Years later, he became the king of dogs, and it is speculated that he is the man raised by dogs told of in a story.
Sometime after becoming the dog leader, he was approached by High Roller, who assured him of the inferiority of humans. High Roller gave the dogs wooden men to replace humans as the drivers of their sleds. The dogs subsequently began antagonizing humans by pulling over their homes in trees.
Dog King has a coffee colored face, largish eyes with maroon irises and black pupils, a small pointed nose and darker brown around his mouth. He also has coffee brown limbs, the front two looking like hands, the back two look like legs. He also has white fur with darker vertical stripes going through it, squarish ears with grey insides and a chalk-white tail.
However, seeing is not believing in this case, as Dog King is really a human. Under his "disguise" he is a young man who looks a bit like Wu Song. He wears a pair of white shorts under the disguise, and nothing else, and has chin length wavy black hair, similar to Wu Song.
Like his subjects, he can cover himself in a large amount of snow and forming powerful snow-boulders to demolish enemies. He is only one of his kingdom to possess icy-breath, howling an icy wind blast to freeze his victims (like ApeTrully and Mr. No Hands) in a matter of seconds. Also, he possesses animal-like strength and power.
Wild, stubborn, brash and aggressive when threatened, he believes that he is truly a wild animal like his fellow dogs and prefers to follow his instinct. Despite this, he is caring for his subjects and extremely loyal to his allies like the heroes of Big Green.
- In "Dog Castle", Dog King so fervently denies being a human that it seems he really believes that he is a dog. At some point between Dog Castle and "Swamp Hippos", however, he reportedly shed his dog costume, indicating he was accepting humanity, but as of "Swamp Hippos", he has returned to wearing it.
- In "Swamp Hippos", when Dog King returns to the wild, he does not return to his snowy kingdom for unknown reasons.
- This possibly due to the considerable distance between Big Green and Dog Castle, which First Squad required help from Sammo to traverse.
- It is currently unknown how Dog King got lost, but it appears that he was very young when the dogs took him in, to the point that he has no apparent memory of his human family. Wu Song, additionally, did not indicate having any knowledge of the general area where his brother was lost but did have great confidence that he was alive and just lost.
- When ApeTrully said about the legend of a man raised by dogs, Dog King appeared as a tiny baby, yet in the picture on Wu Song's wall of him and Dog King as babies, Dog King appears to be at least old enough to sit up, making it unclear exactly how old Dog King was when he got lost.
- However, when brought back to Big Green and reunited with Wu Song, he appeared to know who he was, so he may have been old enough to have vague memories of his human family, which got repressed due to unimportance at the time of him being raised by the dogs.
- It is also currently unknown what Dog King's real name is, as no one has ever called him anything else other than "Dog King".
- When Wu Song first mentions his brother, he evidently expects that his brother would help him with dentistry, suggesting that the practice runs in the family. This seems to be true, as Dog King seemed to be knowledgeable about cavities and knew to be wary of the Terribly Sweet Sundae.
- He has demonstrated the ability to wag his tail. It is unknown how he does this.
- Dog King is the only animal king who is actually a human in disguise.