This elegant image conveys the absolute athleticism, supple grace, confidence of the great, lethal creature – while making it familiar enough that the listening children can imagine the danger as breadbox-sized if they need to.

• 12.011 mixed with a rumble as of a gigantic tom-cat purring.

Hyphenated or not in OED.

“tom cat | tom-cat, n.” OED Online, Oxford University Press, June 2017, http://www.oed.com/view/Entry/203100. Accessed 21 September 2017.