OC doodles/drawings: Things that popped into my mind

It's very self explanatory. I just thought of these new OC's and decided to draw them.

The first one is named X (I know, what a brilliant name) and the other one (as in the huge one with thick fur) is named Boulder.

X- X is a white male cat with bright white eyes, a black "X" on his forehead and chest and an X-shaped pupil. He is the nervous one; any sudden movements cause him to flinch and, occasionally, yowl. He is technically a "friend" of Boulder's...or so he believes.
Boulder- Boulder is a large dark gray male cat with thick fur, yellow eyes, and an X-shaped scar over his right eye (left in perspective). He is also very, very old and his eyes used to be bright when he was younger, but they grew dull as he aged. He's much more powerful than X and he can hardly see or hear. His claws are rather long and he will tear apart anyone if he feels up to it. He's rather rude, tired, slow...but he can, occasionally, be friendly.

X and Boulder belong to @NightRaven