This weird-looking thing is an Irrawaddy dolphin, which lives in the brackish water at the mouth of large rivers. It's too slow to catch its own food. This limitation led to a lot of dolphins being the basis for legal disputes, as late as the 1800s.
The Irrawaddy river winds its way through Myanmar, giving water to local residents and giving its name to a very special kind of dolphin. This dolphin, found in many rivers in southeast Asia, looks like a regular dolphin that got its beak cut off in a gang fight. These days, it's pretty shy. There are a lot of hazards on the river, so when the Irrawaddy dolphin sees boats or anything else that looks risky, it dives.
That wasn't always the case. Dolphins and fishing boats used to have very good relationships. The relationship stemmed from the fact that the poor Irrawaddy dolphin is a heavily-burdened animal. Not only does it have to go around looking like a muppet that has lost its dentures, it is a notoriously slow swimmer. The dolphins herd fish rather than chase them. Fishermen also do this, so when fishing boats went out on the river, the dolphins drove the fish into their nets and the fishers threw the dolphins some of their catch.
Over time, specific dolphins became considered the "partners" of specific fishers. People would even design unique calls for their specific helper dolphins. The dolphins, fools that they were, didn't consider their arrangement legally binding. Once they got food, with whoever was out that day, they were done fishing. It was up to humans to enforce the partnerships.
They did so in court. Person A could take Person B to court, demanding a share of the fish that was caught through the efforts of Person A's dolphin. Meanwhile, Person B could claim that the same dolphin was their helper. Different legal claims to different dolphins at different times of day were constantly a matter of local legal dispute. It probably would have been easier if the dolphins could testify, but sadly that was not an option. The practice of fishing with dolphins slowly fell out of favor - although not because of the legal complications. Modern fishing techniques replaced the older ones, and now dolphins mostly have to avoid fishing boats and catch their own food.
[Source: Orcaella Brevirostris.]