Thanks to their infernal and goblin heritage, Tieblins can see in the dark. 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. 

Your intelligence score increases by 1, your charisma score decreases by 1, and your dexterity score increases by 2.

Tieblins can read, speak, and write in common, infernal, and goblin

Tieblins mature by 12 years old, and rarely live longer than 70 years.

Not necessarily evil, but tieblins are highly likely to incline towards the chaotic alignment. 

Tieblins are size small, but some can grow up to 4 feet.

Your base walking speed is 30 feet.

You know a cantrip of your choice (Thaumaturgy, Message, or Vicious Mockery). When you reach 3rd level you can cast Hellish Rebuke as a 2nd-level spell once with this trait and regain the ability to do so when you finish a long rest. Wisdom is your spellcasting ability for these spells.

You can take the Disengage or Hide action as a bonus action on each of your turns.

When you damage a creature with an attack or a spell and the creature's size is larger than yours, you can cause the attack or spell to deal extra damage to the creature. The extra damage equals your level. Once you use this trait, you can't use it again until you finish a short or long rest.