I saw a shirt at Origins that had a picture of a rhino with the caption "Save the Brown Unicorns."
I bought a shirt at Origins that said:
To do list:
1] Buy a Sword
2] Name it Kindness
3] Kill them with Kindness.
The Million Mick March.
It's an Irish thing. You wouldn't understand.
Edit to add:
Blue Lives Matter.
(Worn by an off duty police officer. I told him that I liked his shirt.)
A few years ago at Origins, I saw one that was
DAMN:
Naked Mothers
Against Dyslexia
There's always a bunch of really good ones at the show
The one I bought at Origins this year:
(https://www.grogheads.com/forums/proxy.php?request=http%3A%2F%2Fwww.aarcentral.com%2Fpics2%2Ftrav.jpg&hash=9583b7d408f1cb63643085b271c7d5d53f0f0998)