Twin-Horned Bolt
Druid Attack 13
A spectral bull appears before you and knocks your foe to the ground.
Ranged 10
Target: One creature
Attack: Wisdom vs. Fortitude
Hit: 2d8 + Wisdom modifier damage, and the target is knocked prone. If any enemies provide cover against this attack, they are also knocked prone.
Twin-Horned Bolt is a 13th level Druid encounter power. On a hit it damages the target and knocks them prone. [PrP:45]