The axis_knight.zip file you have requested: Skins / Axis / Venom (Knight) - 2.2mb is not available. Perhaps try browsing all files for the game Return To Castle Wolfenstein and upload any files you want to share or are missing. This is the only information we could locate:
The Venom (Knight) is another skin based loosely on the original Venom Soldier from the pre-release screenshots (with a bit of Super Soldat thrown in). It uses the standard MP Axis body.