i am unable to spawn any mob eggs except for the animals and the villagers

as I entered a new creative world in minecraft pe 0.9.0 I wanted to spawn mobs with the new mob eggs. as i went to spawn an mob it would show up then disappear.

I expected that when i spawned a mob it would be there in front of me and not disappear.

1. i would take a spawn egg from my inventory
2. i would try to place the spawn egg on the ground
3. the mob would show up and disappear