Your Strength, Dexterity, and Constitution scores increase by 1, and you Charisma increases by 3 

Tieflings mature at the same rate as humans but live a few years longer.

Tieflings are about the same size and build as humans. Your size is Medium.

Regardless of Class, you can choose from one of three creatures to obtain as a minion. Minions can wear specially made armor and wield specially made weapons to increase their power. 

Lesser Imp: a minion version of the Imp. It has lower stats than the regular Imp, with the addition of the Eternal Minion-Fiend  and Ginademon Minion- Rogue traits. 

Pixling: a minion version of the Pixie. It's stat's are similar to the Pixie, but with increased HP and Invisibility instead of Superior Invisibility. Also gains the ability Truesight, and the traits Eternal Minion- Fey and Ginademon Minion- Cleric traits. 

Small Zombie: a minion version of the zombie with decreased health, increased AC, and Improved Undead Fortitude, as well as the traits Eternal Minion- Undead and Ginademon Minion- Undead. 

Your base walking speed is 30 feet.

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.

You have resistance to fire damage.

You know the thaumaturgy cantrip. When you reach 3rd level, you can cast the hellish rebuke spell as a 2nd-level spell once with this trait and regain the ability to do so when you finish a long rest. When you reach 5th level, you can cast the darkness spell once with this trait and regain the ability to do so when you finish a long rest. Charisma is your spellcasting ability for these spells.

You can speak, read, and write Common and Infernal.