Creepers completely ignore cats sometimes, a creeper literally blew up my wife's cat that was near her, i created a new survival world in 1.11.1, i play on Windows 10 edition on PC and she plays on Android 9.

After that, i did some tests in creative mode and spawned and tamed a few cats, them spawned a creeper far away, changed to survival, and went to lure the creeper, i had four cats following me and the creeper completely ignored them, he just got near me and blew up me and the four cats.

I did some more tests spawning more cats and the creepers seems to run away only in specific situations, in most of them they just came near and blew up, killing me and the cats.

OBS: Lots of cats were harmed during those experiments.