Trampling Elephants build?

[MasterBoo]

I heard here about a build that consists mostly of Elephants with boots of the Behemoth. Now that sounds to me like hell of fun and I wish to try it.

Sincd i'm kinda new to the game (Playing only for 2 weeks), i want to know with which nation I should do it (Which of them, got elephants O_O), and how can I equip those normal units with those boots? (Commanders only no?).

Thanks for whoever replies.