The query on Android can refer to a few different titles within the monster-collection genre. Based on current listings, 1. Monster Tamers: Idle Clicker

Follows protagonists Cloud and Verna, members of the guild, as they explore the world of Belana with a mysterious cat-like companion named Nyanners.

It is a high-production RPG that involves befriending monsters and uncovering a "mysterious phenomenon" affecting the world's creatures. Which "Monster Tamers" were you looking for? The parody-filled idle tycoon game? The action-survival game released recently? The Netmarble RPG featuring the Monster Tamers guild?