Java Edition 18w09a

18w09a is the twenty-third snapshot released for 1.13.

Additions

 * Underwater ruins
 * Come in many different shapes and sizes
 * Cold ruins can be found in cold, frozen, ocean biomes - regardless of depth
 * Warm ruins can be found in warm, lukewarm, and deep lukewarm biomes
 * Can generate alone or in a big ruined village
 * You can also sometimes find them slightly underground or slightly above sea level
 * Coral
 * Comes in 5 colors: blue, pink, purple, red, yellow
 * Requires water to stay alive
 * Currently only obtainable in the creative inventory

Changes

 * Phantoms
 * No longer spawn in the End
 * Will now despawn at nighttime
 * Particles
 * Optimized particle rendering slightly