Vernon Grant, according to wikipedia, was an American illustrator born in 1935. So I don't think that's him. No, it's Vermon Simeon Plemion Grant, born in 1902; he was 33 when he did this, and was so well-regarded by Kellogg's for his "Snap, Crackle, Pop" art they sent him on a world tour. He died in 1990.

The pig's okay, but love that cat, and the dog is a remnant of a style that's vanished from the pages of magazines. Pity.