Oil Leeches

A genetically engineered leech of massive proportions the oil leech was designed to consume spilled oils of all sorts when a spill takes place. 
Oil leeches range on average a length of five meters, a width of three meters and at the highest point of their back one meter. They scrape up spilled oil with their mouths which are lined with teeth that is similar to a whale's baleen. 
Oil leeches were engineered to have semi-transparent skins. In this way handlers could better determine when they were becoming full from feeding on the spills they were taken too. After consuming oils the leech's digestive system converts the liquids to methane gas which can be harvested and used to power the alternative fuel vehicles used to transport the leeches from site to site.
While oil leeches are a remarkable example of science, there are several Middle Eastern countries that have banned their import on fears they will escape and consume their marketable reserves of oil. This is a valid fear and concern as a few accidents have happened.
One such incident involved several junior size leeches escaping from their container truck while the driver and transporters took at break at a Mac-a-Doo's Fish and Chips. The juvenile leeches made their way into the kitchen area and consumed all of the cooking grease and oils. A health inspection team was called out and the establishment was shut down while a clean up was initiated. Though undisclosed sources say that the leeches were not to blame and that this particular Mac-a-Doo's had a plethora of other health and sanitation violations that had to be dealt with. Perhaps in this instance the leeches did us all a favor?
Some people do fear that should any oil leeches escape and be lost that they might cross breed with other local leech species creating a hybrid or worse mutate into something worse that could be a hazard to meta-humans or pets.