That smels like something a campaign consultant with a PR or media background came up with.
It does. You can tell they had trouble getting a nickname through their PC team that filters for their fragile, easily offended voter base. Anything remotely funny got shut down immediately as "too offensive", "insensitive", "hurtful" etc...
https://www.foxnews.com/politics/bidens-new-nickname-for-trump-president-tweety