YOU NEED GECKOLIB
This mod adds an animation after a Wither altar has been built, to make players feel more involved in the game and actually feel that a Boss Battle is about to come, instead of the boring, usual, immediate spawn of the Wither, that makes it feel useless.
(You can disable the animation with the command: "/gamerule witherSpawnAnimation false" but this won't take effect on already built altars)
Important:
-This mod is NOT compatible with "Wither Spawn Fix", but if you still want both the spawn animation and the spawn fix you can install "Wither Spawn Fix W.S.A. Compatible"
Works with Cracker's Wither Storm Mod too!
Wither Spawn Fix W.S.A. Compatible!
Excalibur resource pack compatibility! (by Ruseki)
Also try Golem Spawn Animation!
1.6
BUG FIXES:
-fixed a bug that caused soul sand/soil to prevent elevators (Moving Elevators mod) from moving
-fixed a bug that caused the invulnerability time setting (Cracker's Wither Storm Mod) to not work
-fixed a bug that caused worlds to freeze if they were exited while an altar animation was playing (this happened 100% of the time, so even though it didn't cause any data loss/corruption, I strongly recommend updating the mod if you're using an older version)
CHANGES:
-made it so Wither Storms spawn looking in the direction of the nearest player
-did some optimization
-more minor improvements
I realized that this is compatible with Cracker's Wither Storm Mod as well.