The term 'TITLE CHARACTER IN A SEGA GAME' can be answered with the five-letter word 'SONIC'. SONIC is a blue hedgehog who is the title character in a series of video games published by Sega. He first appeared in 1991 and has since become one of the most iconic characters in gaming. SONIC is known for his speed and agility, as well as his ability to spin into a ball to attack enemies. He has starred in numerous games, including the original SONIC the Hedgehog, SONIC Adventure, SONIC Unleashed, and SONIC Mania.