While I was trimming the spurs off this little bantam too, I notice he had a growth on his underside. We affectionately call him Hei Hei from Moana. We have no clue how old he is, he found his way to my mother-in-laws hens about 5 years ago and the owner didn't really want him back because a fox got to the rest of his flock, so we took him in.
Thoughts on what it is? I didn't see it last summer when I trimmed his spurs.
That is just one of those weird defects in chickens. It looks like comb or wattle tissue that is coming out of his side. There are pictures of similar red tissue in inappropriate places on the body, and a few toenails coming out of the body as well. Nothing serious, just an oddity.