[benzesandbetter]

For pseudonymous ones I usually farm old Ice-T and Opgezwolle lyrics. (Ice-T in the case of my HN username).

https://www.thisworddoesnotexist.com/ can also be fun for this.

[bmsleight_]

Wow - https://www.thisworddoesnotexist.com/ is a really useful resource. I would use this not only for usenames, but from brand-names. They are quite a few whihc can be registered as .com

[WelcomeShorty]

Thanks for Opgezwolle! New to me, like it already.