I have a couple with nicknames.
Giving a tree a formal name is a big deal in Japanese bonsai tradition. Nicknames is not a big deal
None of mine have formal names.
Here is "The Hatchling":
It got its name because I'm hollowing out the inside of the trunk. Boon has a big JBP with a hollow trunk named "Godzilla". I thought of "Son of Godzilla", but this one isn't good enough yet, and is still in development so "Hatchling" kinda works.
This next tree has two nicknames: "Little Brother" or "Mini Me":
These nickname refer to a similiar tree that is owned by John Kirby. It's three times as big. It's known as "Big Brother"!
And there's my "Peter Tea" tree.
When I bought it, it had recently been wired by Peter Tea. And I bought it without a pot. I potted it into that pot, which I had by coincidence bought from Peter! So, Peter Tea tree fit. I have since restyled it, and it's going into a different pot this spring.
And finally:
The "Pink Dragon".