Frequent Foes

Frequent Foes is a vanilla friendly mod meant to solve the fact that some mobs are just so incredibly annoying to run into. Frequent Foes gives you a diverse set of ways to summon a variety of these particularly annoying mobs, especially in modpacks where the gain new drops that are quite useful.

As well, the mod adds naturally occuring ways to discover these unique summoning methods, meaning you can figure out their special summoning method just by exploring the world! Currently, the following mobs are supported via Frequent Foes summoning:

Phantoms
Wandering Traders
Skeleton Horses

Each mob also has an associated achievement for summoning it that hints at their method! While it is advised that one discovers the methods themselves, below are the individuals ways to summon them and their enviromental hints.

Phantom: Use a Ghast Tear on a Lightning Rod at night under open sky. Hinted at by a new structure in the Nether, the Netherrod (you'll know it when you see it).
Wandering Trader: Use a loom to craft the particular Wandering Trader banner. When a bell is rang next to it, a Wandering trader comes running (the banner can also spawn in villages).
Skeleton Horse: If you kill a Horse with a Smite V crit at night, it will be peeled into a Skeleton Horse (All Horses at night have a low % chance to make a skeleton horse noise).