Pistons can clock when moving observers next to redstone

Pistons moving while extending can delete blocks and/or move blocks sideways

Piston contraption moves block sideways and causes piston to turn into an item

Infinite "Loading World" Loop

Under some conditions items can duplicate into offhand without updating the GUI

Shulkers are immune to lava

Sponge does not activate when not directly adjacent to water

Shulkers can float

Minecraft Crashes with Unknown Error from tv.twitch

Repeating Stack-trace for Ticking Entity

"Walking" on torches