Tiefling

Much like aasimar are touched by the divine, so to are tieflings. However, they are touched by the divine power of the Betrayer, which warps their form somewhat. They look like humans, but they have some sort of physical aspect that shows their heritage, such as horns, red eyes, scaly and discolored skin, or a bony carapace on top of their skin. They typically want to cause mayhem and murder anyone who gets in their way, but there are a few who determine to live a righteous life despite their background. It is even said that some tieflings who redeem themselves can get the notice of the Father and be transformed to aasimar.
 * Ability Score Increase . Your Intelligence score increases by 1, and your choice of Charisma or Dexterity score increases by 2.
 * Age . Tieflings mature at the same rate as humans but live a few years longer.
 * Alignment . Tieflings might not have an innate tendency toward evil, but many of them end up there. Evil or not, an independent nature inclines many tieflings toward a chaotic alignment.
 * Size . Tieflings are about the same size and build as humans. Your size is Medium.
 * Speed . Your base walking speed is 30 feet.
 * Darkvision . Thanks to your infernal heritage, you have superior vision in dark and dim conditions. You can see in dim light within 60 feet of you as if it were bright light, and in darkness as if it were dim light. You can’t discern color in darkness, only shades of gray.
 * Hellish Resistance . You have resistance to fire damage.
 * Infernal Legacy . You know the thaumaturgy cantrip. Once you reach 3rd level, you can cast the hellish rebuke spell once per day as a 2nd-level spell. Once you reach 5th level, you can also cast the darkness spell once per day. Charisma is your spellcasting ability for these spells.
 * Languages . You can speak, read, and write Common and Infernal.

Variants
As fiends are many and varied, so too are tieflings. You may, if you wish, choose one of the following traits in place of Infernal Legacy.
 * Devil's Tongue . You know the vicious mockery cantrip. Once you reach 3rd level, you can cast the charm person spell once per day as a 2nd-level spell. Once you reach 5th level, you can also cast the enthrall spell once per day. Charisma is your spellcasting ability for these spells.
 * Hellfire . You may replace your  hellish rebuke  ability with burning hands. This alters, but does not replace, Infernal Legcy
 * Winged . You have bat-like wings sprouting from your shoulders. You have a flying speed of 30 feet.