My god! That's not a cat... that's really a monster!
Definitely worth investigating to see exactly what's going on there... does not look healthy at all.
Reminds me of a visit my dad's cat took to the vet. My dad was concerned about this mass of... *something* hanging from the cat's belly, so he went in, as a concerned owner should do.
The vet investigated, and delivered the sad news to my dad.
"Your cat is fat."
Diet time for bonzo...
