People who are very good at something, usually because they practice a lot or have a natural talent for it.
Being superpros at something is usually seen as a very good thing.
Examples:
She is a superpros at playing the piano.
The team has a superpros at scoring goals.
He is a superpros at fixing things.
The cat is a superpros at catching mice.
She's a superpros at singing, she can sing anything!
He's a superpros at drawing, he can draw anything!