Servals (Leptailurus serval) are a medium-sized African wild cat. Sheppard did not have the means to travel to Africa and based most of his drawings of animals observed at Regents Park Zoo. On the strength of these - through which he gained a reputation as one of the finest artists in this field - he was made a Fellow of the Zoological Society in 1949. In the same year, he published ‘Drawing at the Zoo’, one of three collaborations made with The Studio magazine.
Sheppard’s output as a graphic artist was prodigious, but he is less well known today than he might be, partly on account of his early death, at the age of forty-five.