Fish mailbox topperoo

I think you might be having a bit of fun with words!

"Fish mailbox topperoo" doesn't quite make sense, but I can try to break it down:

If I had to come up with a creative interpretation, I might say that "fish mailbox topperoo" is a whimsical name for a fictional underwater postal service that delivers mail to fish in their underwater homes. The "topperoo" part could refer to a special delivery mechanism that allows the mail to be delivered to the fish without getting wet!

Of course, this is just a wild interpretation, and I'm sure there are many other creative ways to interpret this phrase!