Hastes (mob)

My brother wants to make this mob. It is going to be fast. Maybe faster than most mobs. They spawn rarely will but spawn in plains. They will spawn anywhere in the nether and end but rarely. They will find a cave in the nether and end but stay put in the end. They have yellow eyes and a black body. They have 50 health. It hits you dealing 10 damage. It is neutral to players. It drops nothing. If you give one a netherite ingot it gives you anything valuable. It is now your friend. Put suggestions in comments.