World Borders
argyle

Add impenetrable barriers to the sides and bottom of the world.

golden lava
GigaByte

add golden lava

Fly-B-Gone!
Hugues Ross

Hides butterflies/fireflies

Spawn redo
cathaya7d4

Drop-in replacement for default/spawn for more third-party biomes

Easter Eggs / Ostereier
Ineva

Adds various coloured eggs for Easter!

Obdy
Sires

Adds some pretty OP tools :)

Floof
Momo

Add BicBiomeCraft inspired biomes, tools, and items.

Mud
Blocky Player

Adds stylish mud blocks and even blocks you can walk through. Setup traps, secret rooms and much more!

Silver
Jackknife

adds silver ore and tools

Too many ores
TeufloV

This adds 53 new ores. But most of them are useless.