This picture adds meaning to the legend of the M on a tabby cat's forehead. Copied from wiki answers.....
This is the legend of the Tabby "M".
All of us have heard that first Christmas described as a silent night. However, one of God's creatures knew otherwise.
The cat hunted in the cold, starry night. He didn't look much different from the other cats; he was gray in color with stripes the color of charcoal. As he walked down the dark alleyway, he heard crying coming from a stable. He entered the door and saw a mother trying to comfort her newborn son.
She spoke softly. "I don't know what to do. I thought you were hungry, so I fed you. I thought you were wet, so I changed your diaper. I thought you were cold, so I wrapped another blanket around you."
She rocked the infant a few minutes longer and then laid him back in a manger filled with hay. The baby continued to cry.
The cat knew what needed to be done. He leapt into the manger and curled up next to the child. In comforting tones, he began to purr. It was the sweetest lull-a-bye ever heard. The baby quieted and drifted off to sleep.
The woman gently stroked his fur. "Thank you. I don't know where you came from, but thank you."
God was looking down and witnessing the blessed events of His son's birthday. Heard only by the cat, God spoke.
"You have done a wonderful deed this night. Because you cared enough to help this woman, I will mark you and your offspring forever so that people will know what you have done. Her name is Mary and from this day forward you will have the letter "M" on your forehead."
So when you see a cat with the tabby pattern (no matter if it's gray, brown, or some other color) look closely at its forehead and you will see the letter "M". By this you will know that it is a descendant of the cat that comforted the newborn Christ on that first Christmas night