Name: Joey, also known as 'Number One'
Species: Norway rat, mismarked black blazed berkshire varietyy
Age: 5 months
Weight: 245 grams
Birthplace: University of Iowa
Eye colour: blue
Markings: Pure black with a white face, belly, stomach and legs. He has black circles around his eyes with lines that extend downwards onto his cheeks. He also has four vertical lines on each eye-brow.

Extras: Joey is extremely small, around the same size as a 5 week old rat kitten, and is not expected to get any bigger. He does not have a tail, though he is not a naturally tailless rat, it was simply removed by the laboratory.
He has bright red streaks in his hair, and his hair is unusually glossy. He has a notch taken out of his left ear where his tag was removed, a rip in his right ear, and the customary scar of his number on his upper left arm.

General:
Joey is an ex laboratory rat, his allocated number was 1. He was used in physical endurance tests to discover how long he could go without sleep, and also how long he could continually run on a treadmill [link]

His tail was removed to stop it getting in the way of the treadmill, something I remember reading about happening to rats who are used for these sorts of tests. Rats are sometimes placed in boxes and have shocks of electricty run through them when they try and sleep. Joey calls it the shock box.

He is the omega of the group and, like most omega rats, he is humble and devoted to his group. But he's also very intuitive and probably one of the most intelligent rats in the group. He claims that being the omega gives him a lot of time to just sit back and observe, which accounts for why he has an answer for most problems. He always seems to be aware of things the other rats are not, and if anyone wants to know whats going on behind their back, the first rat they talk to is Joey.
Its likely that his size is the only reason he got the omega role; he is a bad fighter and doesn't stand a chance in any physical confrontation. Like most omegas, he doesn't complain about his status, maintaining that he would rather be omega than be ousted from the group altogether. Joey is quite moral, and has set ideas about what is right and wrong. He will speak out against anything he sees to be an injustice, even if he risks being reprimanded for it.
He spends a lot of time riding about atop Warlock's head, and has even power-groomed some of his fur away! He began doing this on the journey back from the lab when he had trouble keeping up with the group. He now even sleeps there from time to time. In fact, he is extremely good with Warlock and Faith has to grudgingly admit that Joey is often the only rat in the group who is able to deal with him. This stems partly from the fact that Warlock has a unique respect for Joey, due in part to the time they spent together on the way back from the lab.
Joey taught Warlock to count up to 9 as a thankyou for carrying him all the way home. Joey knows that Warlock would never hurt him, as he considers it cowardly for anyone to attack a rat so tiny, so Joey has a safety net that the others don't.

Joey is generally merry and happy go lucky. He always tries to look on the bright side of things and offer help when he can. He's kind, compassionate and hates violence; he wouldn't even bite the workers in the lab when they meant to do him harm. He tends to talk at 100mph and often has to be asked to slow down. He seems to have boundless energy and moves so quickly that he can be there one minute and not the next. Despite his tortures in the lab being comparable, or worse, than others in the group, he is very accepting of what happened to him, and never complains about it. He was taken from his mother far too young, possibly part of the reason he's so stunted, and as such he seeks a mother figure in any older female rats he comes across.