The The Grand Caiman Add-on for Shadow of the Tomb Raider: Definitive Edition has 5 achievements.
Obtain a Bronze, Silver, or Gold medal in Score Attack for the Zipacna's Craving Challenge Tomb
Obtain a Bronze, Silver, or Gold medal in Time Attack for the Zipacna's Craving Challenge Tomb
Obtain the Volcano Skill, equip Whispering Scourge Pandemic weapon and Reptile Hide Leviathan outfit
Complete The Wrathful God Side Mission
Complete the Zipacna's Craving Challenge Tomb