I suspect this is a bug.
I was asked to kill these two giant dinos on Oloke. I've done so several times but the mission never completes. Kinda sucks since it seems to be a storyline mission and the game can't seem to progress.

Wow, that will be tough. It's not that killing the big green lizards would be tough for me at this point (I'm equipped out the wazoo). It's the fact a single hit can knock you into a wall where you get stuck and either reload or lose you character (another bug). Well, I'll try. Thank you.

I complete this quest with 4 characters , everyone have 5 + armor & needle pistols\laser pistols .

Good luck !

& remember - you must kill only two big green guys .

Small ones can just bee avoided .

I completed the quest! Thank you!

I just equipped everybody with shotguns and went in there one at a time and then run away after shooting to avoid being hit.