They are lions and tigers who happen to be behaving well FOR THE MOMENT.
As an aside, here's that classic old youtube video on herding cats.
“No cat is safe. To say such a thing is an insult to cats.”
Exactly. Deep down every house cat knows it is distantly related to tigers and lions, and occasionally they will remind you of that fact.
My three are all very affectionate (especially our orange tabby, Apple) but I don’t doubt for a second they’d kill and eat me if they were big enough.