"... the serval, a cheetah-like beast"?
Have you ever seen a serval? Or a cheetah, for that matter? There's one or two servals at Marwel Zoo near Winchester for those who'd like to verify a simple fact.
A serval is, on average, a third of the size of a cheetah and virtually the only thing it has in common with a cheetah is the colouring.
And since it is quite safe to sit in an enclosure with human-reared cheetah (in my experience - they purr, lick your hands and face, and like to lean on you like a big old bagpuss - beautiful friendly animals), I hardly think we that much to fear from something derived from a timid little serval.
"Wild servals are thought to be capable of bringing down a gazelle" - yeah, on a really lucky day, with a very small, weak gazelle with no mates.
Servals normally eat rodents, frogs and birds. Pretty much like your domesticated cat, if the Whiskas isn't forthcoming. Not much evidence of the domesticated cats round here eating small children. Unfortunately.