I couldn't find any information on a specific "787 Downlock" wallpaper in the provided search results. However, I can suggest using the anime-wallpaper package to get anime wallpapers based on scraping from websites.

You can use the following command to install the package:

npm install anime-wallpaper

Then, you can use the following code snippet to get an anime wallpaper with a specific theme (in this case, "787 Downlock"):

const AnimeWallpaper = require('anime-wallpaper');

AnimeWallpaper.get('787 downlock')
  .then(wallpaper => {
    console.log(wallpaper);
  })
  .catch(error => {
    console.error(error);
  });

Please note that this code snippet assumes you have the anime-wallpaper package installed. Also, please be aware that scraping websites may be against their terms of service, and you should respect their policies when using this approach.

If you're looking for a more official or curated source of wallpapers related to "787 Downlock", I couldn't find any information in the provided search results.