Who is this glitterhoof?

[Suzaku]

I keep hearing about him and my googlefu is lacking.

 

[FifthMonarchy]

He's like a CKII version of Caligula's Incitatus: https://en.wikipedia.org/wiki/Incitatus

 

[ghaladh]

Glitterhoof is an horse that a ruler with the lunatic trait might appoint as council member due to an event. There is a player that restored the Roman Empire by playing as an horse and giving all of the landed titles to other horses. ("Horse" is a culture in the game and it can reproduce with humans, producing horse-looking characters). The AAR is quite hilarious.