So I did today's daily trial in the panda plateau and I found a secret creeper area in the cave where you free the pandas. I went in and there was an entrance to an ambush area at the end which is normally supposed to spawn normal creepers. I went in but instead of creepers there was icy creepers there, which seems very out of place for a Jungle level. There is no modifier which replaces melee/ranged mobs with icy creepers.