Number Two

Number Two is a rat who talks because of an experiment with forces well beyond what the scientists should have attempted. Yes, the name is a poop reference. He came up with it himself, and he thinks it's funny.
After the experiment, the surviving rats fled into the sewers and banded together, in that order. Their society came together relatively easily, but not without some oddities, the first of which was requiring something much larger to be their proper leader instead of one of their own. This is less for the need of a leader and more because they see these larger creatures as people who need their assistance in some manner or another to exist in a reasonable manner. This ideology stems almost entirely from Number Two himself.
Number Two serves as the second-in-command for the dragon Tobias, and has since he and his people first discovered the runt dragon hiding in the same area that they wished to settle. They immediately latched onto the rather unhappy dragon as someone who needed the rough equivalent of a hug, and became his minions. This involved gathering treasure and creating traps for unwary humans who came below.
Number Two is a bit larger than the average rat. He excels at paperwork but fails utterly when it comes to spelling or chosing the right word.
He has at least a dozen offspring, but it's hard to tell the exact number because he constantly changes how many he says he has. There may also be a few other rats who he claims as offspring but they're not actually his children. Hard to say if this is something that Number Two does or if it's a talking rat cultural thing. They have a very new culture.
He's possibly middle aged for a rat, and his behavior matches that of an exuberant gentleman with a minivan and enough money for his hobbies.
He continually says wrong but similar-sounding words to what he intended to speak. He is not flame retardant but still stays extraordinarily close to a species that could fry him in two seconds with a sneeze.