From the Shirtpunch.com's interview with the artist:
"Question: What inspired this design?
Answer: Our love of Fringe and the Scooby gang. Can you ever really have TOO many teams of monster hunters? Nope. BTW, Fringe needs MORE love in general! So if you aren't doing so currently, get to watching to insure that it's renewed for a 5th season, PLEASE!!!"