That is an interesting picture, but the image of the animal is vague and blurry. the only thing i can tell is that there is a canine like animal in it.
How do you know it's bullet proof? Have you actually shot at it?
If normal bullets truly do not work, then if this is some sort of supernatural entity, you might want to try silver bullets or bullets and other weapons made out of cold wrought iron. Silver and cold wrought iron are traditionally the weakness to mythological beings such as Faries and demons.
Cold wrought iron weapons are weapons that have been beaten into shape WITHOUT using a forge.
I don't know its the "bullet proof wolf" spoken of in Colm and Knapps book "hunt for the Skinwalker". Based on its unusual characteristics and proximity to the ranch I assume it is. Also fits many of the descriptions of the Shermans first hand accounts.
I have NOT shot it,i don't bring a gun with on my expeditions. So maybe its not so "bullet proof" afterall
Whatever this creature is, I would not even want to shoot it. I have had a close encounter with it at night (ball of light transformed into it)...and I don't think a bullet would do much, and something of that exotic nature probably would not take too kindly to being shot by me.