What is the origin of beastie?

It should come as no surprise that beastie literally means “little beast”; the ending –ie is what is known as a diminutive suffix, a suffix that indicates smallness or, in certain contexts, either affection or condescension. Diminutive suffixes exist in many world languages; you may recognize the suffix –ito in Spanish burrito “little donkey,” or Italian graffito, the singular of graffiti—or the French suffix –ette in kitchenette “little kitchen,” or statuette “small statue.” English has several diminutives, such as –kin, as in napkin “little nape (tablecloth),” and –ling, as in darling “little dear” and gosling “little goose,” but it’s the suffix –ie, which also appears as –y, that’s the most widespread and the most productive.