Asklemmy

Robert'); DROP TABLE Students

Bort

SomethingUncommon

Not sure how uncommon you're looking for, but I think I already did this.

I chose Sage.

According to some quick googling (read: not sure how accurate this is), Sage wasn't in the top 500 names for my birth year, but my given name was top 100.

Though both names I've used have been trending towards more common for most of my life. Looks like my original name is now a top 35 most common, but Sage is still outside the top 100 for females and outside top 300 for males.(Really wish there was more data for the popularity of nonbinary names. I think Sage is probably one of the more popular enby names, so maybe it's not all that uncommon, depending on how you define it.)

Something old, like a name from Sumer, Akkad, Elam, maybe something Hittite.

Epirmupi, Shamsaki, Puzur-Inshushinak, Ninurta, Lugalzagasi, Tiglath-Pileser, Hattusili, Suppiluliuma.

I'm loving the creativity here! To me though, "uncommon" implies that it's not like completely unheard of either. so, my choice would be "Midge"

https://www.explainxkcd.com/wiki/index.php/Robert%27);_DROP_TABLE_Students;--

New full name: Theophrastus Bombastus

Dekkia.

I already use that name everywhere online, might as well put it on my passport.

Batman bin Suparman

Nebuchadnezzar. It has an air of nobility about it and no-one would be able to spell it, ever.

My username is my first name, and I'd say it's already pretty uncommon!

I've already got a name that puts me quite comfortably in the 1% of names used in my country. It's not as cool to have a uncommon name as you think. It's easy to get picked on, you never can buy those souvenir mugs or keyrings with 'your name' and it gets misspelled.

I mean I've written a book where my name is on the cover and one review managed to misspell it...

Otoh. I once met someone on holiday in Ireland that said 'i one met a kid with that name and it was in Croatia, about ten years ago'.

That kid was me. If I had a more common name we'd never have known.

I always thought Ziggy was a cool name.

the ascii null character

Andromeda, probs. I'm a sucker for constellations and stargazing.

Biggus. Now guess what would I change my last name to.

Common, the Rapper.

Not to be confused with Common, the rapper

Belize

Puck like Puck from A Midsummer Night's Dream

Reason: that'd be hot

Jimothy

I always thought that Fox was a cool name for a dude ever since I watched the X-Files. If I had to change my first name, that's what I'd pick.

Octavious Shitwagon

Throckmorton. Saw it in an example problem in my highschool physics textbook and I still think about it

"nil" or "null"

Josaphat

Uncommon in my culture: Makoto (disclaimer: I think Makoto might still be more common in my culture than my real name)

Uncommon in general: Kitty

I already did, but I won't be sharing it in a public forum :P

Doesn't apply for me, but nonbinary folk are great for this question because they all name themselves after random inanimate objects (which is 100% valid)

Adrienne