Ooh, something not holiday/custom item related. :3

Anyway I've been gone long enough that I missed the explanation of what "leashing" a pet does. Is it like making them your active? Or something different?

Any help would be appreciated. Thanks. <3

It makes it so that it's headshot will show under your avatar in the forums for a month, and you get to write a little sentence under the pet's icon.

If I do it for a month will I be able to after that month is up put it back up again without a cost or anything?

You'd have to buy another month if you wanted to display it longer :)