The arkentran_ut2k4.zip file you have requested: Skins / Skaarj / UT2004 Arkentran Skin - 4.5mb is not available. Perhaps try browsing all files for the game Unreal Tournament 2004 and upload any files you want to share or are missing. This is the only information we could locate:
MacTom27 submitted a nice skin for the Skaarj, that's called Arkentran. It comes with 4 teamcolors.