@Lee-White Awww yeah! This kind of thing is like copyright catnip for me! Because I look at this and think -- wow, I don't know! This is not cut and dry.
Okay, so to start there's no specific litmus test for a copyright infringement. It requires the consideration of multiple factors.
The case that Lee mentioned is Art Rodgers vs Jeff Koons
This involved taking a 2D photo and turning it into a 3D sculpture (complete with process notes given to the company tasked with actually making the sculpture from Koons that effectively said "Make it look more like the photo") Courts found that making a 2D image 3D was an infringement.
In this case there's no question you are pulling from a single image. Which would tend to count against you in a copyright infringement question.
BUT you are clearly not directly copying the image.
New camera angle, lighting, redesigning characters so they have volume. New pose for bird and frog.
Also the Moose looks decidedly scary with the glowing red eyes.
The feeling I get from the original is "happy and friendly", the new one "threatening and unnerving". This latter goes toward the concept of "transformative use".
If I had to make a definitive call on this from a legal standpoint, I would say this is not an infringement. From a personal standpoint, I would be cautious. It would not surprise me to get a cease and desist from the original artist, so I'd want to have my arguments lined up for the reply. And one of those arguments would be to get an opinion from a licensed intellectual property attorney.