(Image credit: RJ Palmer) Inventing creatures can be an opportunity to let your imagination run wild, but only up to a point. Stray too far from realistic anatomy or what’s physically possible and your designs won’t hold up. We spoke to five experts in the field to discover how their create characters that are completely imaginary but that feel like they could be real (also see our roundup of character design tips for more pointers). Mastering gesture gives Ed Binkley's creature creations a high level of believability (Image credit: Ed Binkley) For many creature designers, a solid understanding of anatomy is key. “I’m a firm believer that a fantasy artist cannot alter or distort anatomy convincingly, human or otherwise, without knowing anatomy and body mechanics thoroughly,” says veteran artist and educator Ed Binkley , who taught figure drawing and concept art for 30 years.…