Because I could almost swear that it's some kind of reference to Monster Hunter 4's Gore Magala and/or its Frenzy Virus.
Or it could just be a weird coincidence. ¯\_(ツ)_/¯
EDIT: For the lazy ones that dun wanna reed da wiki artkle: "In large monsters, the Frenzy Virus causes a notable discolouration of the skin, fur, feathers, or hide, resulting in a dark purple hue all over the body."
You definitely read too much into this.
"In most prize boxes, the [no personal attacks] artist/developer/intern causes a notable discolouration of the skin, fur, feathers, or hide, resulting in some strange hue all over Haven."