Doodles, it seems, are not exclusive to Google. While the search engine made the format popular, others have started doing similar things, like Bing's background images synced to the various occasions.
Clicking on the custom logo leads to a search for "Charles Schultz," like on Google.
It's hardly the first doodle DuckDuckGo has run, it's been doing it on occasion for the past couple of years. All the doodles share a common theme, a variation of Dax, the DuckDuckGo mascot and logo.
This time around, it's wearing a Snoopy hoodie. In the past, Dax has been a pirate, an astronaut and Leonardo Da Vinci.