Since we have yet to find a way to resolve this issue civilly, it's found its way into the hands of the law. According to the Twitter account congress-edits, which documents every Wikipedia revision that comes from an IP address within Congress, a congressperson just changed the entry by removing it from the "Male characters in comics" category.
This congressperson may be correct. The comic's creator, Jim Davis, told Mental Floss that the character doesn't have a gender. "Garfield is very universal. By virtue of being a cat, really, he’s not really male or female or any particular race or nationality, young or old. It gives me a lot more latitude for the humor for the situations," he said. However, another Wikipedia editor by the name of DrCliche thinks this shouldn't be taken so literally. "This is a comment explaining the philosophy of Garfield’s universal appeal," they wrote.
Whoever edited the entry — or perhaps a different congressperson — also got rid of a comma in the following sentence: "Part of the strip's broad pop cultural appeal is due to its lack of social or political commentary; though this was Davis's original intention, he also admitted that his 'grasp of politics isn't strong,' joking that for many years, he thought 'OPEC was a denture adhesive.'" (The comma used that be after "joking that").
We'd say the correct usage in that situation is ambiguous. Kind of like Garfield.