At times, I play 1. ... a5 as Black.
Offbeat opening variations; I'm all for them

Do you get interesting games? I guess you might develop the bishop to a6 in time which might cause problems for white castling. I think odd looking moves that haven't any obvious refutation are the best. They can also make your opponent think you are worse than you are which can be an advantage.
I have read quite a few threads here lately about slightly odd openings, some of which are quite old fashioned (the most recent being 2.Qe2 in response to the French). Quite a lot is made of whether masters play this and if it is sound and so on. But the elephant in the room here surely is that most players here have no hope (or even aspiration) to be a master, and even openings that have been refuted in theory can work perfectly well for ordinary players playing other ordinary players. I know that as we move up the grades we all want to play well and maybe improve, but I (and many other players I am sure) like to play the occasional (frequent?) oddball opening because it makes for a more interesting game from the start than rattling off the first 15 moves from MCO. It's also handy for lazy people like me who can’t be bothered to learn reams of opening theory. And just occasionally it all kicks off and we can pretend to be Paul Morphy for five minutes. What could be more fun than that?