Minecraft wiki entry for Development_versions, associated text: The animation for spiders is now twice as fast
End portal frames' texture changed from the Java Edition Beta 1.9 Prerelease 3 texture to the current Java Edition Beta 1.9 Prerelease 4 texture.
The swamp biome's look has changed from the Java Edition Beta 1.8 look to its current Beta 1.9 Prerelease look.