Custom Emoticons and Cultural Imperialism

My team in Scotland dislike the American Cultural Imperialism that is the grey ship-it squirrel. We wish to replace it with our own bonnet-wearing native red squirrel (below), or at the very least allow us to indicate that a PR should be shipped without paying homage to our American cultural overlords. On Slack, we can use the shorthand :aye: to have our preferred squirrel indicate ship-it readiness, but not on github. It’s a troubling oversight. Please extend us this facility.