Bugbears are cat people: sneaky, dangerous, serving underground elves, always ready to pounce on you, always spying on you

Boars as pets for orcs, giant boars as mounts for dwarves and halflings, and demon boars as protector spirits of a forest

Talking about giant beetles and how I used them: pack animals for the underworld, war elephants for goblins and the like, or car sized monsters in dungeon corridors

Talking about giant bees, giant wasps, and how I used them: like Aliens in a hive, and as mounts for lizard people

Talking about bears, laser eyes, and summoning angry flying bears

Talking about the basilisk (also known as the cockatrice)

Talking about giant apes

Talking about a simple 2d6 system I use for online gaming. One opposed roll to determine initiative, to hit, and damage.

On the things I do for prep: random tables, monster lairs, jotting down some shallow ideas, run with it in such a way that I don't need to improvise in depth but that shallow encounters point to other shallow encounters, take note of what happens at the table and let that inspire more ideas that build on the previous ones. Last session's shallow idea thus turns into the seed for the next session's good idea.

The gods, the realms, confusing and overlapping portfolios, how even the evil ones need to provide a benefit.