gigantic penis
An implausibly large penis, even more disproportionate to its owner than a huge penis. A penis comparable in length or girth to its owner's torso deserves this tag.
When uploading images featuring penises of this size, keep in mind that they may be deleted for violating Danbooru's Terms of Service ("penises that are larger than two heads in size").
See also
This tag implicates penis (learn more).