Thankfully there was never a third
Unless you count
Full Frontal
who has a ridiculous name even by Gundam standards.
Quattro is Char's 4th identity. Originally he was Casval Daikun, then Édouard Mass while he was hiding out in Europe as a minor, then Char Aznable when he infiltrated the military academy, then Quattro Bajeena after the One Year War.
Right. The meme is referring to identities he chose for himself.
Quattro Vageena?
What about full frontal?