Ancient Aberrant Dragon

Multi Elemental: This dragon is an ancient dragon that was born of multiple elements, this dragon has resistance to all elemental damages.

Breath weapon. This dragon can use an action to use it's breath weapon for any element dealing 5d10 elemental damage with a range of 25 ft and an area of 15 ft cone.

Slashing Claws. As an action any creature within 10-7 ft take 5d12 slashing damage, any creature within 6-1 ft take 5d12 bludgeoning damage. The slashing has a range of 10 ft and a area of 25 ft across, on a successful Dex 15 save the player takes 1d4 force damage.

Ground Pound. As an action this creature can it's front feet on the ground and anything within 50 ft must succeed on a Dex 15 save or fall prone and take 5d6 damage. The area is considered rough terrain.

Tail Swing. This attack has a range of 15 ft and an area of 35 ft, anything in range must make a Dex 15 save or be going 50 feet and take 5d8 bludgeoning damage.

This creature gets bonus action to move or fly 50 feet in any direction.