Shampoo is a hair care product that is used to remove dirt and other unwanted substances from someone's hair. It has appeared once in a Sonic the Comic strip; Professor Frank N. Stein was hoping to create a shampoo for people with green hair (like him). However, just as he had achieved this feat, Igor's new dog barked at him, causing the professor to jump backwards and destroy his creation.
Elsewhere, the footer of a Pirate S.T.C. strip saw Skull warning Boomers not to drink bubble bath, instead suggesting to drink shampoo as it can "wash your ingrowing chest hair"). This advice brought at least one angry letter in a following Speedlines. In Sonic the Comic Online, April Fools' Day saw Megadroid get his own back on the Humes by putting shampoo in their coffee maker, as revealed in Issue 230's Speedlines.