A zebra is standing outside and eating grass.
Some type of zebra grazing in a field in a zoo type environment
Excepting the lower legs and the hair tufts along the neck, a zebra is basically albino and grazing in an area of minimal ground cover, near a fence, against a backdrop of trees.  
A horse that is standing in the grass.
An animal that looks like a horse with stripes grazing on some grass.