Answer:
Stealthy as a shadow in the dead of night, cunning but affectionate if given a bite. Never owned but often loved. At my sport considered cruel, but that's because you never know me at all.
What can bring back the dead. Make us cry, make us laugh, make us young. Born in an instant yet lasts a life time?
What always runs but never walks, often murmurs, never talks, has a bed but never sleeps, has a mouth but never eats?
There are several different kinds, but the one you pick doesn't do its job. What is it?
Voiceless it cries,Voiceless it cries, Wingless flutters, Toothless bites, Mouthless mutters.
What is so fragile that saying its name breaks it?
Difficult
Animal
Easy
Food
Funny
Kids
Logic
What am I?