Interestingly, lions have been interbred with tigers. They are called “Ligers”. Probably not in the wild though, they don’t really share the same habitat.
The differences in the reciprocal crosses is most likely due to the different reproductive strategies of both species.
A Tigon has been successfully bred with a Tiger to produce a “Ti-Tigon”. This Ti-Tigon could re-merge with a Tiger population, bringing a certain % of Lion ancestry to that population.
Similarly, our hypothetical “Humanderthal” could re-merge with a human population, bringing a certain % of Neanderthal ancestry to that population.
Napoleon Dynamite liked Ligers.
Ligers can stand 12 feet tall