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.
I wear a red robe, with staff in hand, and a stone in my throat.
What has a mouth but can't chew?
RUGBY = 9, TENNIS = 14, FOOTBALL = 12, HOCKEY = 16, SWIMMING = ?
I'm not man's best friend, I'm their enemy, I can mark your end, yet you do not see me, I am very small, but very tough, If you have me, then you have it rough.
What is so fragile that saying its name breaks it?
Difficult
Animal
Easy
Food
Funny
Kids
Logic
What am I?