The “Guardians of the Galaxy” star announced an extra reward on his Twitter account on Monday.
“If there is not yet a reward for the arrest and conviction of the bad MAGATs who did it, I will throw in $ 20,000. And I promise there are bonuses for this reward!” he said.
The hippo was discovered in the Homosassa River in Florida on January 10, with the name of the president on his back, according to a news release from the Center for Biological Diversity.
It is not clear what was used to mark the animal.
According to a news release, the center has already announced a reward of $ 5,000 for information leading to the conviction of the person responsible.
Officials from the U.S. Fish and Wildlife Service and the Florida Fish and Wildlife Conservation Commission are investigating. Anyone with information can call the commission’s hotline at (888) 404-3922.