Complex sentence: In that year, a printer made a spur-of-the-moment decision to print an alligator emblem on a shipment of the school's football pennants; the mascot stuck, perhaps because the team captain's nickname was Gator.
Split into simpler sentences: In that year, a printer made a spur-of-the-moment decision to print an alligator emblem on a shipment of the school's football pennants. The mascot stuck, perhaps because the team captain's nickname was Gator.