This is just what I got from googling their birthdays so it could be inaccurate. Some I'm pretty sure are wrong but I don't know what else to put so yeah. If someone knows the real birthdates please comment them along with the year.
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These are from the top of my head. (First three)
Bloody Painter- October 1st, 1980.
BEN Drowned-April 23rd 1990
Ticci Toby-April 28th, 1997
Jeff the Killer-June 2nd (year unknown)
Homicidal Liu-(UNKNOWN)
Sally Williams-April 5th, 1958
Clockwork-November 6th, 1996
Kate the Chaser-June 25th, 1995
Jane the Killer-September 1st, 1985
Nina the Killer-(UNKNOWN)
Lulu-(UNKNOWN)
Lazari-December 25th, (year unknown)
Judge Angels-April 2nd, (year unknown)
Nurse Ann-October 31st, (year unknown)
Puppeteer-July 25th, 1974
Laughing Jack-Sometime in the 1800s
Jason the toymaker-(Unknown)
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The Slender Brothers' birthdays are unknown if that is what you're wondering. Also, I'm kinda surprised that so many creepypasta were born in April. I even share the same zodiac sign as Sally and Judge Angels! I was really close to having the same zodiac sign as BEN and Toby though. If you have any other birth dates I could add please comment them!
-Lovesick