The animal on the cover of Google Advertising Tools, Second Edition, is a white-headed capuchin monkey (Cebus capucinus). The capuchin monkey is named after the Capuchin order of monks because the color of its head is said to resemble the monk's cowl. Native to parts of Central and South America, capuchin monkeys can be found in a range of habitats, including rain forests, mangrove forests, and wooded areas.

Traveling in groups of 6 to 20 monkeys, capuchins spend much of their day foraging for food. While they prefer fruit, capuchins will also eat leaves, nuts, flowers, insects, spiders, and sometimes small birds and lizards. Because food can be scarce, capuchins have to come up with creative ways to feed themselves. For example, they have been observed using tools to crack open the tough nuts of shells and teaching their offspring how to use these tools.

Scientists postulate that the challenges these monkeys face in procuring food has helped develop their brains. Capuchins' high intelligence and small size make them good pets, and they are sometimes trained to act as assistants to paraplegic people. Most famously, perhaps, the capuchin monkey is the traditional companion of the organ grinder.

The cover image is from Wood's Illustrated Natural History. The cover font is Adobe ITC Garamond. The text font is Linotype Birka; the heading font is Adobe Myriad Condensed; and the code font is LucasFont's TheSansMonoCondensed.