If you do he will take good care of your stock and his Irish tunes will be heard. Many of the faerie realm are known for their great knowledge, wit and wisdom. The most common example is the leprechaun. No one has ever managed to cheat him out of his hidden pot of gold or magic shilling, for he is very old and has seen all of the tricks and deceptions that humans can employ. At the last minute he always finds a way to divert his captor's attention.
Many faery folk have a fondness for horses.
The Leprechaun is probably it's biggest fan. They are known to hang out near horses. They have been known to protect horses. Other fae such as elves and gnomes can be petitioned to protect horses. I got me three big wishes, and I wanted so many things.