A cat on Reddit went viral for being “ripped”, but it’s actually a rare condition that makes animals put on muscle on top of muscle. There is no gym routine or diet that gets this little guy to his bouncer-esque state; instead, it’s Myostatin-related muscle hypertrophy.

One Redditor commented, “I bet he purrs like an engine.”
“Cat gonna cuddle you into submission,” said another.
Another person chimed in with a joke: “This the cat she tells you not to worry about.”
“Talk about a cat that would fuck you up for not cleaning out the litter box…” oh my, how accurate!
Myostatin-related muscle hypertrophy is a rare condition; it causes animals to build muscle without intending to do so. Myostatin is the protein produced by the body that stops muscle cell growth. Most bodies have signals that tell us to grow or stop growing muscle; it keeps things in check and makes sure we look relatively normal.
But when there are deficiencies in myostatin, it makes the animal “bulk up”.
All number of animals have shown evidence of lacking the protein — sheep, cattle, dogs, and even people.
Popular Science explained: “Each of us has two copies of the gene encoding myostatin. Inheriting one mutated copy makes you heterozygous for the gene, and animals with that pattern are unusually muscular and strong without being soobviously abnormal that people write case reports about it.
“It’s only when you’re homozygous, meaning you have two mutated copies, that you become something of an anomaly.”
This extra muscle is not really a good thing evolutionarily speaking; species can be negatively impacted by the extra bulk. Instead, it seems to better to have ONE mutated copy of the gene. Heterozygous horses and whippets were the fastest in separate studies.
So it’s probably not something you want to go out and find, but it sure does make for one interesting-looking cat.