Earliest the Mysterious Stranger spawns?

I started a new vault in fallout shelter and got a mission to find the Mysterious Stranger 6 times and I get a pet for it!

But I am still pretty early game and am wondering if anyone knows if there is a minimum vault size for him to start spawning? I really want the pet so any advice would be helpful.


Solution 1:

In Fallout Shelter, there is no set time or required vault size. The Mysterious Stranger randomly spawns and when you find him, you get some extra bottle caps. You have to be quick though as the Mysterious stranger only stays for about 5 to 7 seconds.