A redheaded identical twin. In addition to being exceptionally rare, they are also likely to be smarter, funnier and more attractive than you.
Student A: "Yo! Did you see that? Twingers!"
Student B: "Wow, I never knew they actually existed..."
A particularly rare occurance in where twins share red or ginger hair. Gingers have been proven to be becoming more and more rare and the probability of twins is quite small making twingers a particularly beautiful piece of God's creation
'Let me introduce my two friends Richard and Simon; they are brothers born on the same day and have ginger hair!'
'Pleased to meet you guys, I've never met real live Twingers!'