Sounds like an unlikely combination, but a recent article in Slate magazine points out that the former have been used to market the latter for a while now. Here's an excerpt.
When did bears get to be associated with bathroom hygiene?
Over the last few decades. The preponderance of bears on toilet-paper packaging — along with angels, babies, and puppies — derives from the dominance of the major players in the bath-tissue industry. Procter & Gamble, Georgia-Pacific and Kimberly-Clark together control about two-thirds of the market, and their brand icons — the Charmin bear, the Angel Soft baby, and the Cottonelle puppy — showed up in the United States over a 15-year span beginning in the late-1980s.
The first commercial brands of toilet paper emerged 100 years earlier, at a time when the product was rarely associated with specific images. In the 1880s, most were sold as "medicated paper" for treating hemorrhoids or other health problems, and decorated with wordy display copy reminiscent of the labels on Dr. Bronner's Magic Soap.
The Scott Paper Company became the first to offer toilet paper on a roll in the 1890s, and its products were marketed under private labels that each had their own advertising scheme. Many used words and pictures to connote luxury, as in The Waldorf and The Statler, two brands named after fancy hotels. Some showed images of ladies in ball gowns or gentlemen riding in horse-drawn carriages.Images courtesy of the Virtual Toilet Paper Museum
By the 1920s, the Scott Company had created its own genteel paper-products spokesman named Mr. Thirsty Fibre. Created in the mold of dapper brand icons such as Mr. Peanut and Rich Uncle Penny Bags (or Mr. Monopoly, as he's now known), Mr. Thirsty Fibre resembled a fuzzy, angry Abraham Lincoln — a gaunt man in a top hat and tails, brandishing his fists at moisture.
A few other manly toilet-paper icons populated the early years of the product, like the grizzled seafarer from packages of Life Guard, but the industry soon adopted a more lady-like approach. The Charmin brand got its start in 1928 with a woman's cameo silhouette on the package—a "charming logo" that connoted femininity and elegance. (Virile cleaning-product icons like Mr. Clean and the Brawny Lumberjack wouldn't show up for another few decades.)
There's more at the link. (The Virtual Toilet Paper Museum has lots of images of 'historic' toilet paper . . . if one can call it that!)
Funny thing - all my friends who live in real bear country (including Alaska) find the Charmin bears to be somewhat less than convincing portrayals of reality . . .