Maine Coon is a breed of domestic cat. Its actual origin is unknown but they look quite wild and they're usually pretty big. The biggest specimens weigh up to 11.3kg. But Rupert here is not just pretty big. He's huge. He's a "mega monster cat", according to experts. Heck, this thing can probably kill you if he decided to.
Rupert is now 9kg, which is less than his biggest cronies. But he's only two years old. By three he will be much bigger, say the vets, growing to the point in which he would be at least 14kg.
For comparison, male bobcats can get up to 14kg too. The Canada lynx goes up to 10.8kg, while the Iberian can reach 12.7. Only a male of the Eurasian lynx would be bigger than Rupert, at 18-27kg.
Still, Rupert will be 14kg of muscle, teeth, and claws. A domestic cat who looks pretty much like a real lynx. I'm not sure if I would feel safe around one.