Innate Spellcasting. The Ogre's innate spellcasting ability is Charisma (spell save DC 13). The ogre can innately cast the following spells, requiring no material components:

At will: Darkness, Invisibility

1/day each: Charm Person, Hellish Rebuke, Hex

Legacy of the Lower Plains: The ogre is somehow shaped by the powers of the lower plains. Pending its origin a DM may give it one of the following traits to reflect the varieties of Half Fiend Ogres. It also grants the ogre an additional 1/day spell.

Balorspawn: Fiery Soul. When these creatures dies, it explodes; each creature within 10 feet of it takes fire damage equal to its number of Hit Dice.

1/day Burning Hands

Night Hag's Progeny: Fear Incarnate. This creature has immunity to the fear condition, and has advantage on intimidation checks.

1/day Sleep

Crushing Blow (Geryon's Champion, Recharges after a Short or Long Rest). As a bonus action, the creature gains a bonus to the damage roll of its next melee weapon attack that hits within the next minute. The bonus equals its Strength modifier (+5)

1/day Command