It depends on the reason for it's problems and thereby dying, but the most common smell of most any animal that is dying from starvation, or the inability to eat and produce energy for sustaining life is a faint smell of acetone.
This smell occurs when the body starts degenerating/burning muscle-tissue in order to provide energy to sustain life.
No, basil does not smell like cat pee.
Yes, ammonia has a similar smell to cat urine.
Cats eat cat food, so therefore their breath smells like cat food. Think about it with humans. If you eat pizza, doesn't your breath smell like pizza?
Its the smell of hops that comes from the breweries.
Your bra smells like you, and by rolling on it the cat can "mark" the "person smell" with the cat's own smell. In essence, the cat is claiming you as his.
Your fish has issues
Death smells different at various stages of decomposition, some describe it like rotten meat only much worse. It is not a smell you will like or will ever forget.
Yes, cats seem to smell more like bananas. To test this yourself, go to your cat and go REAL close to it and have a whiff of it, if it does smell like a fruit (preferablly bananas) its a pure bred cat!
Cat urine can sometimes smell like ammonia because it contains a high concentration of urea, a compound that breaks down into ammonia when it is exposed to air. This ammonia-like smell is a natural result of the breakdown process of urea in cat urine.
Death
Your dog may smell like cat pee because it got sprayed by a Tom cat. A cat's spray often smells like pee.
Cat pee has a strong, pungent odor that is often described as sharp and ammonia-like. This smell is due to the presence of ammonia in cat urine, which can be especially potent and unpleasant.