He's just a big cat!! I have a giant too! He's six 1/2 months and weighs probably six and a half by now. He's lanky too! It'll be interesting to see how big he gets... His momma was teeny tiny, I just don't understand...
Well, my little Missy was 3 pounds at that age (and she is STILL a petite, small boned, little white kitty today, at age 8, and weighs 7 pounds) On the other hand, my Spikey is a moose, and he was 9 pounds at that age, and is 13 pounds today. He is NOT fat, but is tall and muscular and solid! --But, he is STILL my little baby!!
Now I know my cat is a whale. She just turned 2, and is 13.7 lbs, and she is not a big cat. I have her on low cal as well as regular. I know she needs to lose at least 2 lbs, slowly. My other cat that is 6 weighs 7 lbs, and is a small dainty cat.
Muddy & Koko are littermates and Sage and Dakota are litter mates. Billie is my stray foster.
I understand that the "average" (and that's average in big hypothetical quotes) is about 1 pound per month up to around 9 months old, then it tapers down from there. So Nimby at 7.8 pounds is probably going to be a big boy.
What size are Nimby's paws? My Muddy's paws are HUGE right now (little black snowshoes). Dakota's paws are normal size, so I think that even though he is big right now, he's going to stop growing younger. Koko will remain dainty like her cousin Scarlett (7-1/2 pounds at 2 years).