The letter 'q' in particular is derived from Ancient Greece, specifically the Greek letter Koppa -pictured in a few forms below – and as you can see, 'Q/q' resembles the same shape as Koppa.

Out of the world's 195 countries, only one starts with the letter “Q”: Qatar. A mere 8% of all languages use the /q/ sound, although English speakers often pronounce it as /k/ (like in "Kangaroo"), which appears in 90% of the world's 3,000 languages and dialects.

q, seventeenth letter of the modern alphabet. It corresponds to Semitic koph, which may derive from an earlier sign representing the eye of a needle, and to Greek koppa. The form of the majuscule has been practically identical throughout its known history.