I love all the names for it! I call it a goomba...reminds of the creatures in Mario for some reason haha. Both of my male cats have it... one is overweight and one isn't. That's interesting that the extra skin is used to protect in a fight!
http://www.catinfo.org/docs/Food%20Chart%20Public%209-22-12.pdf
Control f to find trader joe's. This lady is a vet and has spent hours (even days perhaps) compiling the nutritional content of various cat foods. One of my cats recently had struvite crystals but he absolutely hates the hill's...