Re: So this 'Separate species' question
All of the Panthera cats (lions, tigers, leopards, jaguars) can and will interbreed both in and out of captivity, though jaguars have a difficult time of stepping out with other cats due to the South Atlantic Ocean being in the way. Mostly it's due to male lions, who apparently will screw anything which holds still long enough. (Hmm. Sounds like some other males I know.) Male tigers are somewhat more circumspect, or at least less attractive to other kitties. Tigons (male tiger/female lion cross) and ligers (male lion/female tiger cross) are often fertile. Crosses with leopards and jaguars are much less so. Note that the biggest cats result from having a lion as the father; other kitties lack the gene complex that lionesses have which cuts back on the size, so ligers and litigons (tigons crossed with lions) tend to be really, really REALLY big cats. Here's a nice big house kitty: https://i.pinimg.com/474x/30/d9/25/30d925cf64948b1985e6ba75087d883f--ligers--years.jpg and here's daddy house kitty, son house kitty, and soon to be lunch: https://i.pinimg.com/originals/b9/f1/e2/b9f1e2ca81aeebf28229b7445f82c5de.jpg
See, they're nice friendly kitties, just the thing for inviting into the house.
I like wolves. They're less likely to roll over you and crush you by 'accident'.