You can eventually try to trap the Chupacabra at the Snaggletooth Rock in Puerto Rico (center star on the map). On your first visit, you can get a fur sample from the barbed wire at the brother's farm (right star), and you must return this to Mews before you can go after the Chupacabra. According to the DNA test, the fur is from a coyote.
When you return, the first farmer has decided to trap the Chupacabra. Drive to meet again with his brother, who suggests that you use your Jeep to corral the three spotted goats at Snaggletooth Rock.
Drive to the area and steer around the three goats (two are together) and herd them to the Rock. Once all three are in the grass circle, leave the vehicle and meet the goat herder, who has set up the large crate with chains and locks.
Well, you can TRY to catch the Chupacabra with it.
Not really
Yes, you can find proof of The Jersey Devil, Bigfoot, Nessie, and the Chupacabra. (see related question)
You can't. But its tooth is proof enough that it is an unknown species.
Take it back to Mews. Once you have gotten the photo of the Yeti footprint, and proved the other three cryptids (Nessie, chupacabra, and the Jersey Devil), Mews will send you to track down Bigfoot.
You have to look for Bigfoot/Yeti in the Himalayas, the Jersey Devil in New Jersey, the Loch Ness Monster in the Loch Ness in Scotland and the Chupacabra in Puerto Rico.
You need a photo of Nessie at Loch Ness, a tooth from the Chupacabra from Puerto Rico, and egg shells from the nest of the Jersey Devil in New Jersey. (see related solution)
When you first start the island and you get the paper about Mews needing the evidence of ONE cryptid to get your reward, you end up needing to search for 4: Bigfoot, the Loch Ness Monster, the Chupacabra, and the Jersey Devil.
you have to have three goats and.. that farmer dude to help you
After you have confirmed the other three cryptids (Nessie, Chupacabra, and the Jersey Devil), and brought back the inconclusive footprint from the Himalayas, Mews will send you in pursuit of Bigfoot, which is similar to the Yeti.
There are 3 you have to prove: Nessie (Loch Ness) Chupacabra (Puerto Rico) New Jersey Devil (New Jersey) You can't get what you need to prove the Yeti, so you are sent to find Bigfoot.
You get the fur from a fence in Puerto Rico. Back at the lab, you run a DNA test, but it turns out to be ordinary coyote fur.
You need a photo of the actual Nessie, a tooth from the chupacabra, and egg shells from the Jersey Devil. (see the related questions below)