I must upload this again.

You can remove tags by clicking the "Edit" button on the left side under "Options" rather than re-uploading it due to an incorrect tag.

josemartinez said:
I must upload this again.

You can just edit the tag away by pressing the "edit" button at the base of the image and then remove it.

I cannot remove originals tags.

Must be a bug. I can't remove it either.

why this happens when I try to upload something? :(

You're welcome.

For those confused about why the "canine" tag couldn't be removed, it's because the tag "dog" was also on this post, and the tag "dog" IMPLIES the tag "canine". You have to remove the "dog" tag in order to remove the "canine" tag too.

If you ever run across this scenario again, it's good practice to search our Implication list page to see if the tag you're trying to remove is implied to something else. In this case, you'll see that "dog" implies "canine": http://e621.net/tag_implication?query=canine&user=&approved=all&order=tag

Thanks :)

Hmmm so the belly is because of the dick?