Hauling a small (approximately 1 dton container, with lifesupport module attached) for a land developer. Turned out to be several thousand small frogs which he released in a specific area of the destination planet.
The GM stated that the locals (TL-3 or 4, more or less) were exceedingly superstitious and considered frogs to be evil spirits, refusing to live anywhere near where frogs might be found.
Seems the land developer had been restrained from gaining possession of the land the locals had been living on, and was prevented from using force to remove them; they had to leave of their own volition. He had been able to purchase a small plot of land near the desired area, and that's where he released the frogs.
Unfortunately, the locals knew he had done so, knew why, and knew we had been the ones that had actually brought the blasted things, so they really didn't like us. They didn't get violent, they got mean. They reported us to the Imperial Colonization and Planetary Development Service (ICPDS), who had been the ones restricting the developer in the first place, and THEY got bureaucratically violent.
We got banned from every planet in the domain that was under ICPDS supervision for transporting livestock without proper documentation. The form read "Reptile" instead of "Amphibian." (Actually, our Merchant, with both Liaison and Admin of 5 and Bribery of 4 blew all three rolls; all 1's. The GM was laughing his assets off for five minutes after that one.) It took almost ten years gametime before they relented, and that was only because most of the characters had died.
Simon Jester