This article contains lore created collaboratively by the Blaseball community. It is just one of many Rumors that we've found in the Interdimensional Rumor Mill. You can find more Rumors about Rat Mason at their Rumor Registry.
Rat Mason and Their Pet Rat
Rat Mason, a young adult human, is never seen without the company of their pet rat. The pair's team has often reported finding them atop stairway railings or lockers while waiting for practice to begin, seemingly always moving. Graffitied walls spotted in and around Al Pastor Memorial Stadium are assumed to be Rat's work.
Prior to their career with the Tacos, Polk first entered the public eye when they held an elaborate marriage ceremony between their pet rat and a wild rat they referred to as Penny in the middle of Los Angeles. The reception was attended by several dozen mice, rats, squirrels, and other rodents, and afterward Polk paraded the couple through the streets with a megaphone, shouting "These Rats are Gay and there's Nothing you can do about it!"
Looking for a place to divert energy from mischief and hang out with people besides their pet rat, Polk signed up for Al Pastor's kickball league out of genuine interest. Finding out upon entry of the first scheduled day of practice that the league was indeed, not for Kickball, came as a shock, but the Rat duo quickly developed a knack for Blaseball. With their pet resting atop their head at bat, and promptly placed onto the field after hits to run bases together, the two have came to be known as a hit or miss duo, crucial to the Unlimited Tacos lineup.
The name Rat Polk, reported as their name in media outlets after the rat marriage, has been the only name to stick with them throughout their Blaseball career (albeit modified during the Wyatt Masoning). 'Polk' may or may not be short for 'Polkadot'.