Valenar Trample( Player's Guide to Eberron, p. 141)
[Fighter Bonus Feat, Racial]
You are trained in Valenar cavalry techniques emphasizing trampling your opponents into the ground.
Mounted Combat (PH) , Elf, region of origin Valenar,
When you attempt to overrun an opponent while mounted on a Valenar horse, your target cannot choose to avoid you. Both you and your mount can make one attack (your mount with a hoof and you with a melee weapon) against any target you knock down, gaining the standard +4 bonus on attack rolls against prone targets.
A fighter can select Valenar Trample as one of his fighter bonus feats. This feat counts as Trample for the purpose of meeting any requirements or prerequisites.