No, they don't have to actually trademark it themselves. It means that the Supreme Court said "this parody product is more of a commercial product than an artis

No, they don't have to actually trademark it themselves. It means that the Supreme Court said "this parody product is more of a commercial product than an artistic expression". Therefore, go back and argue about trademark law (which concerns itself with commercial products) and not copyright law (which concerns itself with expression). Now, if they didn't mass produce the product and try to sell it, that would be different. Painted a dog playing with the toy and post that picture on the internet: 1st amendment.