I want to play a red dragon rogue and sneak my giant ass around and stab people in the back! logical!
An adult red dragon actually does have proficiency in Stealth in 5e, giving it a +6 to stealth checks. So yah, a red dragon actually can be pretty sneaky.
You can then give the red dragon a couple levels in Rogue. Put your Expertise in Stealth for an impressive +12 to sneak, plus you get Sneak Attack.
