For animals:
* Mabangis (fierce, ferocious)
* Ligaw (wild, untamed)
* Gubat (forest dwelling, refers to animals that live in the forest)
For behavior:
* Mabangis (fierce, ferocious, uncontrolled)
* Malupit (cruel, savage)
* Mapanganib (dangerous, risky)
* Walang pakundangan (reckless, without regard)
For nature:
* Ligaw (wild, untamed, referring to nature)
* Walang-taong (uninhabited, deserted)
The best translation will depend on the specific meaning you want to convey.
For example:
* "A wild animal" would be "Isang mabangis na hayop" or "Isang ligaw na hayop"
* "A wild party" would be "Isang mabangis na party" or "Isang walang-pakundangan na party"
* "The wild beauty of nature" would be "Ang ligaw na kagandahan ng kalikasan"