Black moor attacking ping pong fish

[Dane.w]

Today I got a ping pong fish and put it in my tank it’s 40 gallons, I have a black moor and regular goldfish, the black moor won’t leave the ping pong fish alone and I’m worried it may die of stress please give me some advice, unfortunately I don’t have a spare tank

 

[Fishmanic]

if it keeps up, you might consider returning the ping pong fish for the sake of it's health.