this is in the newest snapshot 14w19a but it says this version doesnt exist.

when in the new gamemode 3 (spectator mode) when approaching hostile mobs they will despawn when you get close to them.
Describe what you thought should happen here
the new gamemode should allow you to approach any mob or player and click on them to spectate.

Peaceful mobs like animals or villagers will stay but neutral or hostile mobs despawn when in a certain radius of the player
Steps to Reproduce:
1. spawn hostile or neutral mobs
2. ...move away and enter gamemode 3
3. ...move back towards the mobs and when close they will despawn