Biltong is made from about anything on legs - maybe even out of things that do not have legs.
The biltong shop close to one gate of Pilanesberg National Park had elephant,lion,kudu,beef,springbok,ostrich and some others (that I just can't remember).
After purchasing of everything mentioned above except for lion, a series of (highly scientific) sensoric tests took place with the following results :
Beef
tasty.
Springbok
the best. Really, ambrosia.
Ostrich
Tastes like air-dried chicken. Yuck !
Kudu
not as good as beef. Dog ate it.
Elephant
Greyish. Stringy. Awful. Dog refused to try.