7 is the 12th member of 1234567890 and an apprentice cannibal under the teachings of wise old 8. When 7 was officially born as a number, he was put in the same room as 8. 8 taught him everything he knows... including the art of cannibalism. This changed 7's life forever.
7 first gained notability when the 7th Harry Potter book came out. Nobody knew what number came after 6, so 7 introduced himself and became famous. Now he is one of the most popular numbers ever. But he will never become more popular than number 2.
7 lived out 7,777 years of fame before something happened. He recovered from this something, but then he was framed for a crime! 8 had done the unthinkable... he had eaten another number! 9 had been eaten by 8, and 8 was already set up for 8 years in prison. What better to do than blame 7 for the crime? 7 had been there, so it was easy to blame him.
7 went on the run to avoid getting caught by 4. He ran for 7 years, hoping he could avoid capture. He thought he was finally safe, and started a life in the Bubble Bass Empire. He was there for 7 minutes, and then Bubble Bass walked up. He asked if 7 supported him. "Who are you?" 7 and Bubble Bass had a fight then. 7 won. 7 now lives with & in Keyboard Village.
7 sometimes thinks he's really lucky because he, aka is just a lucky number, so he tries to be a showoff which just makes him look like a big N00b. With this nature he convinced massive amounts of people into believing that the number 7 is lucky.
7 was replaced by ⍼ during the Great Meme Reset to avoid people from saying 67. 7 years after this happened, 7 faded from existence.