Mob Spawn Effect or Animation

This is nothing too serious, but I am making a request to add some kind of effect or animation for hostile mobs spawning naturally.  Right now, when hostile mobs spawn, they just appear into existence which can be odd especially when walking around at night and just seeing a zombie for example that just was not there two seconds ago.  My suggestion is to make particles, similar to the smoke particles created by campfires or from killing other mobs, burst from the spawning mob when it appears.  However, I think this effect should only be applied to overworld hostile mobs that spawn on the surface at night since this would be the only time any mob in the game would just come into existence like this.  Overworld passive mobs like pigs have been in the world for a while and not just spawned in, (at least that's how I like to think about it).  This is the same with Nether and End mobs.  That's really all I have for this suggestion.  I hope you take this into consideration.