MechaTarrasque
Hero
This month's Unearthed Arcana, by Keith Baker, Ruty Rutenberg, and Ben Petrisor, features Dragonmarks! "This month, we explore how to make a character who bears a dragonmark, a mystic sigil that appears on the skin. The mark is a source of magical power and enhances the bearer’s ability to perform certain tasks. In the world of Eberron, each mark is tied to specific bloodlines. The families that carry these marks joined together to form the Dragonmarked Houses, powerful forces that dominate different industries. Even though these marks are associated with Eberron, you could explore using them in other worlds as well."
It's an 8-page PDF. "A dragonmark is a mystic sigil that appears on the skin. The mark is a source of mystical power and enhances the bearer’s ability to perform certain tasks. In Eberron, each mark is tied to specific bloodlines." WotC notes that this material is also in Wayfarer's Guide to Eberron, available as a PDF over on DMs Guild.