Source: Unearthed Arcana 85 - Wonders of the Multiverse
You have absorbed primeval magic that gives you an echo of the might of giants. Choose one of the kinds of giants listed below. As a bonus action, you can call on the power of your giant magic to imbue your attacks with additional power. The next time you hit a target with a melee or thrown weapon attack within the next minute, the attack has an additional effect depending on the origin of your giant magic:
Hill Giant. The target takes an extra 1d6 damage of the weapon’s type. If the target is a creature, it must succeed on a Strength saving throw or be knocked prone.
Stone Giant. The target takes an extra 1d6 force damage. If the target is a creature, it must succeed on a Strength saving throw or be pushed 10 feet away from you in a straight line.
Frost Giant. The target takes an extra 1d6 cold damage. If the target is a creature, it must succeed on a Constitution saving throw, or its speed is reduced to 0 until the start of your next turn.
Fire Giant. The target takes an extra 1d8 fire damage.
Cloud Giant. The target takes an extra 1d4 thunder damage. If the target is a creature, it must succeed on a Wisdom saving throw, or you become invisible to it until the start of your next turn.
Storm Giant. The target takes an extra 1d6 lightning damage. If the target is a creature, it must succeed on a Constitution saving throw, or it has disadvantage on attack rolls until the start of your next turn.
The saving throw DC for these effects equals 8 + your proficiency bonus + your Strength or Constitution modifier.
You can use this bonus action a number of times equal to your proficiency bonus, and you regain all expended uses when you finish a long rest.