Kermitron. My nickname, Kermi, is a shortening of my surname. One time when I was about 14 some friends were talking hypothetically what kind of businesses we'd run and what we'd call them. My friend Victa for instance has the initials VIP, so if he ever opened a business it'd have to incorporate that somehow.
My imaginary business name was Kermitron Enterprises.
I register as Kermitron on any website I sign up to where Kermi is already taken or not long enough to be a valid username.
In the even rarer even when Kermitron is taken, I use kremitorn. This is a reference to an mp3 that circulated in the 90's of a comedy skit portraying Kermit and Big Bird stoned out of their minds. At one point, Big Bird refers to Kermit as 'Kremit'. So I flipped the Rs in Kermitron with their vowels.