There is a story behind it all: the three-legged orange just dropped one day from the roof of my mom's garage when it was about 12cm long. His mother quickly took him back and taught him never to trust humans.
My mom tried to domesticate her, but she was too wild - she most likely lived her all life in the nearby, very unforgiving swamps. The three-legged kitty decided to stay with my mom, but his mom stopped coming a few months later.
A few months later, this other standard-issue cat started coming to my mom's garden - and he was completely mad about protecting this three-legged orange. He will walk behind him wherever the oragne goes, and will chase off any other cats getting close to him. He grooms the orange one excessively, without an appointment or even an invitation. They share the same facial features and have the same fur texture - soft like a rabbit. The standard-issue cat also has very short legs, so genetics could be at play. That is why we assume they are brothers.
In any case, in the process of getting the three-legged one civilized (getting him to the vet) - I got bitten so bad, that I was put on observation for rabies. They didn't believe a three-legged normal kitten could do that much damage. I am out of the woods now, and this video shows their brotherly love in my mom's garden.