"Gentle giants" -- that's a term commonly applied to draft horses. They are massive, true, though some breeds are no taller than many riding horses; but the largest among them are awesome, almost overpowering in their physical presence when you are close to them and can measure your own puny insignificance against their immense height and girth, their unimaginable strength. If they wished to, they could crush you like a bug.
And yet they don't. Though draft horses, like any other equine, can rebel against their human handlers, or panic and bolt (as a team did in Iowa during a July 4th parade, with tragic results), mostly they bear patiently with the small two-legs that buzz about them, commanding their obedience and ordering their lives.
It is fortunate for humanity that they are so biddable, and not just in terms of safe handling. For most of recorded history draft horses have pulled the plows and wagons of agriculture and transport, skidded logs out of the forest, hauled ore from the mineheads, mowed fields for the hay that fed them through the winter, dragged graders down dirt roads, and in multitudes of ways powered the human milieu that selectively bred them to their massive greatness.