When suggesting that the marozi is a lion-leopard hybrid it is necessary to understand that a person describing it as "a cross between lion and leopard" may simply mean it bears resemblance to both of those creatures and does not mean it is literally a hybrid.
The first observations of spotted lions (marozi, Panthera leo maculatus) by westerners were made by Colonel Richard Meinertzhagan in 1903 when he described darker lions with rosette-like markings in the Kenyan mountains. Meinertzhagen had heard of the marozi several times between 1903 and 1908, but no official notice was taken of it and it was probably dismissed as native myth.
In 1924, Captain A Blayney Percival, renowned game warden and brilliant naturalist (in the days when this meant shooting things!), reported killing a lioness and her cubs which were all very clearly spotted. The lioness was described as being no less spotted than her cubs. It was possible some individuals retained their juvenile spotting much later than usual. The existence of cubs is often cited as evidence that the spotted lioness could not have been a leopon hybrid. However, female big cat hybrids are often fertile, producing offspring if mated to a non-hybrid big cat. It is the male hybrid that is sterile.