Now to turn THAT DAMN FISH into something useful to anyone that isn't in Styros RPG group... :p Or in other words, instead of slagging it off, heres how I would have run the same plot to make it more Trek in my mind.
Here be Monsters
Would suit TOS or TNG
OK, a giant spaceborne lifeform is terrorising a spacelane. Several ships have been destroyed and several crews are dead. The local authorities have sent a small fllet to intercept it, all of which was destroyed.
They have turned to Starfleet to help out, and the players have been assigned the mission.
The nature of the creature is up to you, from extreme giant catfish laden with unfeasable torpedos :D or giant space amobia... Depends on the era, TNG or TOS, the older the cornier (rule of thumb). The motivations should range from a mother protecting her children (Perhaps its near a stellar nusury or asteroid patch where the young are) or simply feeding or territorial protection.
Motivation is the important aspect as that will give the clues hat will help the players deal with the situation. Ideally they will protect the creature, discover why it is taking action and either negotiate with the traders to avoid their favourite space lane, or simply learn some form of communication and arrange a truce...
Alternatively they could fight the creature only discovering its motivations when injuring it, and maybe having to take over the creatures role and heal it in the meantime.
For a quirk, perhaps hunters arrive to kill or capture the creature, and the crew have to deal with both sides?