The Perishers his bathtime struggles with Wellington usually turn into epic battles. Boot's favourite food appears to be links of sausages, and his attempts to consume these in advance of Wellington provide the basis of many episodes. Boot was originally drawn with a short tail (on one occasion he met a bob-tailed sheepdog, and on hearing the name decided to call his own tail Fred), but Maurice Dodd later discovered that real Old English Sheepdogs' tails are docked, and so over the course of several years Collins drew his tail shorter and shorter until it vanished altogether – Boot still appears completely
The Cartoon History of the Universe each published collection, Gonick thoroughly cites his sources. But rather than relying upon an ordinary, typeset bibliography, Gonick sustains his unorthodox style and exuberant tone as the Professor takes the reader through a cartoon tour of his sources. Because much of "The Cartoon History" covers evolutionary science, physics, astronomy, and ancient history, Gonick has referenced original writings on these subjects, rather than relying on secondary sources or anthologies. Some of these primary sources are national epics, cultural writings, or holy scriptures, such as Homer's Iliad, the Rig Veda of India, and the Bible. In this way he prompts his readers