I have 3 or 4 large goldfish that hang out under a fish feeder on a creek at my hunting lease. Not certain, but they are probably survivors that got off the hook while fishing for catfish many years ago. Either from a local bait store or Comet Goldfish from Petsmart. I am amazed they keep showing up because the Brazos is not far downstream and we have some crazy rushes of water that flood the creek during big storms.
I noticed those comet and bait store goldfish we used had a few plain colored fish in the mix, but the grown "gold" fish are obvious. More than once I remember seeing odd shaped or colorful ones with the bait fish sometimes. I am certain some Koi, Shubunkin, Goldfish hybrids, or who knows what else ended up mixed in the store bait tanks and or pet store feeder tanks.
These pictures are at least 6 years old. I know one of the colorful ones was still around this September, but much bigger now. The darker one of the pair in this first picture is probably one of the plain colored goldfish. Or could be a small carp. Maybe this will help with the ID yea or naw. The "gold" goldfish are no doubt when you catch one. I gave strict instructions to my lease partner to release them anytime one get's caught.
"Life moves pretty fast. If you don't stop and look around once in a while, you could miss it"