Answer:
I am an animal named after the animal that I eat.
A spent round or a slimy critter.
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 do pandas have that no other animal has?
My first is twice in apple but not once in tart. My second is in liver but not in heart. My third is in giant and also in ghost. Whole I'm best when I am toast.
Almost everyone needs it, asks for it, gives it. But almost nobody takes it.