Super excited psychotic overly happy harlequin jester puppy.
His personality is straight up overzealous insane madness joy.
or a melty blushy puppy

Pretty much is just always happy and excited and cute and adorable.
Usually depicted in art as a puppy,child,toon,youthful,slightly cub.
Also is micro a lot and is always in a preyish position in vore.
Most take advantage of the cute prey puppy cause he looks sooooo tasty
but Chester always survives vorish encounters because diamond can't be digested.

Chester isn't just a puppy. He IS a diamond.
He's a barrage of little harlequin diamonds that form an adorable puppy.
He can teleport by transforming into a cloud of scattered diamonds and re-appearing close by.
Whenever he's very excited (which is all the time) diamonds flutter around his body in the air.

Art by: Grau! http://www.furaffinity.net/user/grau