"Corrupt" Status Effects (Status Effects with levels over 127) don't work on mobs like they should. They work on players, just not mobs. For example: Levitation 128 instantly sends me to the ground. However, for mobs, it sends them straight up. AFAIK this works with /effect, I haven't tested it with potion effects.
Steps to reproduce:
/summon Creeper
/effect @e[type=Creeper] levitation 1 128
Those amplifiers aren't supported