100% cockerel- or Rooster.
He has his white saddles highlighted for you! How thoughtful! Lol
Does he have some nice round white ears? That's one more marker for the Dutch Bantam- which is a possibility.
Does he have short legs? Dutch.
If he has small ears, he may be an OE or a Japanese Bantam.
Because you have found him, not raised him, we can only guess on his age. He looks to have reached full maturity.
His tail is nicely long, extending into a nice 'S' shape'- Dutch bantam trait.
His feet look nice and slate gray- also dutch trait- legs short- also marker.
Also- looks like his wingspan runs the length of his body- very Dutch trait
No Serema. He doesn't present upright enough or hold his wings 'at attention'.
My favorite rooster was a Dutch & he was brilliant. Very sweet natured though he liked to complain.
When they crow, the last note is low, not high- unlike the 'standard' cock-a-doodle-doo! It's more of a 'cock-a-doodle- Uh-ohhhh' -- which always struck me as funny.
What a wonderful find! He looks really happy you are helping him, too.
I hope you wanted/needed a pretty little roo!
Here's an example photo of some dutch bantams.
