I appreciate your enthusiasm. It's always great to see people invested enough in their communities to give them a mascot.
However, as mentioned in the sticky, /tan/ limits itself to the documenting of existing board-tans, and deliberately does not engage in proactively creating them for others. Board-tan creation should be an endeavour of the concerning boards themselves, not something we do only to then shove the end result onto them.
I'd advise you to go to /mental/ and make the same proposal there. Since you've already got a base to work off from, it should be easier for the other users to respond and start brainstorming.
Good luck with your project! I hope it's successful and shall be keeping an eye out.