Answer:
What peels like an onion but still remains whole?
It's black and every time it speaks it says its name.
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.
To you, rude would I never be, Though I flag my tongue for all to see.
It can be white or blue or black, Humped or have a horn. And when it talks it sings its menuets, as it's travelling the depths.
I hold two meanings. With one I may be broken, with the other I hold on. What am I?