Wait until after the Monster Hunt is over. Fangbeasts are always scarce during Monster Hunts.
Fangbeasts | 5 hits | spawn from all normal animals (cows, chickens, pigs), Hot Pepper, Carrot, Trees, some Buildings (stable, hatchery, farmhouses), Fangbeast Trap (5 gems), Glimmeregg Bunny, Season 5 Training Dummy (keep checking the Inventory Guide for up to date places of where fangbeasts can spawn from as new items are added which also spawn these monsters).
Thread on where to find Monsters