At Centaur town search for an NPC called Dionysus Silverstream (located in the house north of the fountains). Say Skeletal Centaurs and he will tell you to kill 12 and return to him for a reward.
You can find Skeletal Centaurs at Mordenthal's dungeon (located NE from Stonecrest). Kill 12 of them (or more) and return to Dionysus Silverstream. Say Skeletal Centaurs, Yes and he will reward you with a Scroll of Horse Friendship and 1500 experience points * your current level.
You can use the Scroll of Horse Friendship for different quests:
1st way:
Take Scrolls of Horse Friendship to Malachai Fatebringer (located at Centaur Town) for one of the following items: (Keyword: Scroll of Horse Friendship)
You will also be rewarded with 2000 experience points * your current level.
These items can be traded to other NPCs for other items:
Take 2 Assassin's Blades to Daran Lightfoot (located in the Inn of the Adventures at Stonecrest) for a Broken Ethereal Key. Keyword: Assassin Blade , Yes. You will also be rewarded with 1.500 experience points * your current level.
Take 3 Robes of Hell to Julian (located at Stonecrest) for a Gloom Staff. Keyword: Robe of Hell, Yes. You will also be rewarded with 2.500 experience points * your current level.
Take 4 Grim Blade of War to Sir Mordenthal (located at Mordenthal's Castle) for a Dark Gem (also a small chance for a Dark Gemblade). Keyword: Grim Blade of War, Yes. You will also be rewarded with 1.500 experience points * your current level.
Take 5 Bows of Centaur Slaying to Resha (located in a house near the east entrance of Stonecrest) for a Cloak of the Archer. Keyword: Bow of Centaur Slaying, Yes.You will also be rewarded with 2.500 experience points * your current level.
2nd way:
After you have 10 Scrolls of Horse Friendship search for a wandering NPC called World Wild Horse (yep, you guessed correctly, it's a Horse). Talk to him (Keywords: Work, Teleport Locations and he will offer to teleport you (for a fee of 1 scroll) to one of the following locations:
Lighthaven Bridge Arakas Stonehenge Annabelle's House Arakas Brigands Windhowl Entrance Blackblood's Castle Silversky Castle Raven's Dust Stonehenge Raven's Dust Desert Stonecrest Plaza
He also teleports with you.
Note 1: You can do this quest as many times as you want.
Note 2: There is a bug and World Wild Horse doesn't spawn in game.
NPCs involved: Dionysus Silverstream, Malachai Fatebringer/World Wild Horse (Optional), Sir Mordenthal/Daran Lightfoot/Resha/Julian (Optional).
Quest Reward Synopsis: One of the follow choices: