Creepers do not expand and flash before they explode.
Linked issues
Comments 5
Related to MCPE-7929
This is a duplicate ticket. It does not affect single player games, or the host of a multiplayer LAN game. However, a player joining the multiplayer LAN game does not see the creeper expand in size before exploding. If you have further comments on this bug, please post them on MCPE-7929.
Is this on single player or on multiplayer?