What is the relation of me and my cousins baby?

You are not second cousins, although a lot of people think so. The baby is your first cousin, once removed. This may sound odd, but that's the way it is.

Edit: For general information, the children of cousins are second cousins. The children of second cousins are third cousins.

Your cousins baby is considered your second cousin, just as your mom or dad's cousin would also be your second cousin. Your second cousins child would become your third cousin, and so n...

A cousin I guess.

you are second cousins