A while ago, I created an add-on that allows you to create a mob-grinder in one block. I reworked that add-on for 1.16 and future versions. This add-on adds a block that grinds mobs by placing their spawn eggs inside. The interval would understandably take some time in order to balance everything, though this is not an efficient solution to big mob-grinders.
Empty Mini mob-grinder
Made from cobblestone, iron bars, and a stonecutter, this block is the heart of this add-on and it grinds the spawn eggs you give it.
You can use a lever to activate and deactivate it.
Interval between productions are 30s - 45s.
Will take the following spawn eggs:
Bee
Blaze
Cat
Cave spider
Chicken
Cod
Cow
Creeper
Dolphin
Donkey
Drowned
Elder guardian
Enderman
Evoker
Ghast
Glow squid
Goat
Guardian
Hoglin
Horse
Husk
Llama
Magma cube
Mooshroom
Mule
Ocelot
Panda
Parrot
Phantom
Pig
Piglin
Piglin brute
Pillager
Polar bear
Pufferfish
Rabbit
Ravager
Salmon
Sheep
Shulker
Skeleton
Skeleton horse
Slime
Spider
Squid
Stray
Strider
Tropical fish
Turtle
Vex
Vindicator
Wandering trader
Witch
Wither skeleton
Zoglin
Zombie
Zombie horse
Zombified piglin
Zombie villager
Production
The production ranges at average 1-2 items.
Video demonstration
Installation
Make sure to turn on ALL experimental gameplay features to enjoy this add-on to the fullest.