Your Dexterity score, and two other ability scores of your choice,  by 1 

Demi-Leprechauns  mature at the same rate humans do and reach adulthood around the age of 20. They live much longer than humans, however, often exceeding 150 years.

When you reach for your pocket, you always find 3 coins (copper) waiting. When pulled from your pocket, these coins vanish into smoke unless accepted by another sentient creature within 1 minute.

Level 3 = Silver
Level 7 = Gold
Level 15 = Platinum

Demi-fey have the average about 3 feet tall and weigh about 40 pounds. Your size is Small or Medium

Your base walking speed is 25 feet.  When using your Move action, if all 25 feet are used at once, you may immediately move an additional 10 feet.

When you roll a 1 on the d20 for a skill check, an ability check, or a saving throw, you can reroll the die at disadvantage and must use the new roll.  If either die in this re-roll is lower than your proficiency modifier, your Leprechaun heritage calls power to this moment.

You have advantage on saving throws against being charmed, and magic can’t put you to sleep.

You can speak, read, and write Common and Sylvan. The Sylvan language isn’t secret, but halflings are loath to share it with others. They write very little, so they don’t have a rich body of literature. Their oral tradition, however, is very strong. 

Given the Human ancestry, you may also pick one additional language.