Many months ago, I released a high-quality vector version of Tux that I made in Inkscape as SVG and PNG.
Somewhat recently, I needed to make a black and white version for a project.
You can get both the color and black and white versions in both SVG and high-res PNG at the Tux github repository.
These versions of Tux are licensed under the public domain, but if anyone asks, Larry Ewing made the Tux mascot in the Gimp and I made these versions in Inkscape.