Nature Science Journal
When I started working for Nature, they almost tested my versatility to breaking point. Each commission needed something different - for example in the very first issue I worked on I did a very cartoony depiction of four scientists as aliens. After I filed the work, they asked if I would like to have a go at the cover - a 'concept cover'. They wanted me to make it look like an old pulp sci-fi mag, and that meant hand-drawing all the text (including the small print above the title) to get that authentic pulp-fiction feel. That cover, Many Worlds, is below. It's the third thumbnail - just after the four aliens I mentioned.
The other classic request was, 'we want a Holbein. We need it Tuesday.' That's here, too.