Karla is an open-source, grotesque sans-serif typeface designed by Jonathan Pinhorn. Karla isn’t perfect — the spacing is set a little wide and some of the kerning looks a little off, however, this font has tons of character and there really aren’t any other quirky grotesques like this that are available for free. Karla is available in two weights — normal and bold — each with matching italics.
If you are looking for an alternative to Karla, I recommend checking out Supria Sans and Maple. I think Schneidler would make a nice font combination paired with it.