Halloween Teasers
From Homestar Runner Wiki
Every year since 2007, The Brothers Chap have been making Halloween teasers, which display a message saying that the Halloween toon will be put on the site later in the week. In every teaser, Strong Bad has on a ridiculously realistic costume and it's never the same in the real toon. Also in every teaser, you can decompile the image to see words written behind the silhouettes.