White Box Appears Around all Mobs and Dropped Items

While testing the new biomes, when I reached a Savannah biome suddenly all the mobs and dropped items got white boxes appearing around them. It also persisted with every item drop and mob even after leaving the biome, changing the video settings from fancy to fast, and restarting the game. Strangely, the boxes seemed to match the hit-boxes of the object (With the player character as the one exception).