When I start Minecraft with Animania 1.4.6 in 1.12.2, everything starts lagging; as a player you get catapulted randomly around, graphics go crazy and all the mobs, Animania and vanilla, move very strangely...
I don't know why, and restarting and relaunching everything doesn't help.

Apparently it was caused by a combination of other mods, sorry for the disturbance! :)