Hey, Zahard's lackeys, I'm gonna send each and every single one of you to hell !! So tell the Canine People over there for me, someday I'll make sure Yasratcha joins you bastards in hell too, so tell them to keep their fangs sharp and wait for me !!
Baylord Yama (베이로드 야마, Bae’ee’rohdeu Yahmah) is a High Ranker and the seventh Slayer of FUG and is widely known as the King of Bayroad.Madoraco said he is one of the richest FUG Slayer by making money with sports entertainment and secret gambling on the side.
Baylord Yama has two brothers, an older brother and a younger one who serve as his second and third in command
(To Karaka) "!! I'll never let him enter my ship unless he brings Deng Deng to me!! If he wants to get in anyway, he'll have to follow the laws around here and beat me in a fight first! I DARE YOU, KARAKA!! I DARE YOU!!"
(To his Gang) "Hmph... Such arrogance. How dare they set foot in my territory. Karaka must be out of his goddamn mind. That little kid's sure grown up a lot."
(To Mule) "If you break your promise to me and hurt my clan in any way, I will find you and your master, that old fart, and tear you to pieces and devour you right down to the last bone."
(To Mule) "Remember that. Indeed dogs always repay you if you take good care of them. Except me, of course. Because I'm 'King of the Dogs".
(To Khel Hellam) "If there is something you wanna take from me whether it's my slayer title or a single grain of sand, you will have to fight me for it. And I would be happy to fight you."
(To Lo Po Bia Yasratcha) "That's enough!! Stop messing around. If you really want the canine people, you'll have to get past me first!! I'm their king..!!" 
This was the original background history of Yama that SIU made on his blog before it was completely changed in the WEBTOON (main story) - not canon anymore.
Before Baylord Yama was first shown in Season 3, author SIU released information about Yama on his blog. The story was completely different with Yama that we currently know.
Baylord Yama was one of the Pitbulls that battled in Bayroad and it is said that he was the strongest Mad Dog of all time.
In the pit, he was a God of Death (사신, 死神, sahshin) who drove opponents to their doom and people came to call him "Yama, the Lord of the Dead" (야마, 죽은자들의 왕, Yahmah, Joog’eunjahdeul’eui Wahng, or “King of the Dead”) out of respect for him. Later, he killed his own keeper and successfully became the only Mad Dog to ever escape from Bayroad and climb the Tower. Although no exact details are known regarding this procedure, it is rumoured that Imort (이모르트, Ee'mohreuteu, or “Immorte” etc.), another Slayer of FUG, was involved. 
After becoming a Ranker, Yama returned to Bayroad with FUG’s power at his back and killed the previous owner of the pit. Hence, he simultaneously became the King of the Mad Dogs and a Slayer of FUG. Because of this, it has been frequently hypothesized that the domination of Bayroad was the final condition he had to fulfil to become a Slayer. 
It is rumoured that he is currently using the enormous revenue made in Bayroad as a weapon to build mysterious pleasure and entertainment facilities (adult entertainment involving alcohol, drugs, and sex) everywhere throughout the Tower and therefore expanding his influence and power. However, he has never shown his face since becoming a Slayer.