UNITSYM.DAT is identical to UNIT.DAT except that it has beefed up Symbiot units. It is ideally suited for single player games as well as multiplayer games that need a powerful random element to spice things up!

Just rename UNIT.DAT to UNITBAK.DAT and UNITSYM.DAT to UNIT.DAT for nasty Symbiots that strike fear in the hearts of their opponents.