Eh, I see what you’re saying, but regardless of its quality, you’re still publishing it by sharing online and it’s good practice/common courtesy to credit sources. At the very least it points people down the path to find more if it sparks an interest.
It’s literally a 1:1 copy of an existing work. What you were doing with it at the time is irrelevant. What a weird way to behave if you want to be seen as an artist yourself.
It calls into question all the other stuff you’ve posted. Were any of those uncredited reproductions of someone else’s idea?
“No”, I’m sure you’ll say. But now we’ll never know.
Be better, man. Credit where credit is due.