Ms and Sony have no mascot. Only Nintendo and Sega ever got one and they're Mario and Sonic. Both are widely known even to the non-gaming audience (like grand-parents). Masterchief is mostly known to people that played Halo. And for Sony, there was Crash but now they have none. However, I don't think that really is a problem. Mascots are only useful for advertisement.
How many cups of darkness have I drank over the years? Even I don't know...







