All mobs have half their health. It takes 10 hits from a fist to kill Creepers, Skeletons, Zombies. 8 to kill Spiders, Big Slimes, and Villagers. 6 to kill Cave Spiders. 5 to kill Ghasts, Cows, Pigs. 3 to kill Bats, 2 to kill Small Slimes, Chickens. 1 to kill Baby Slimes as usual though.
MCPE-9289
Incorrect Mob Health
Resolved
Works As Intended
0
(Unassigned)
Unconfirmed
Phone - Android - HTC One
All mobs have incorrect hp
0.10.4, 0.10.5, 0.11.0, 0.11.1
Retrieved
Works As Intended. Pocket Edition uses the old player strength, with an attack strength of 2 heart points (barehanded damage).
I recommend checking the Minecraft Wiki prior to reporting an issue on this bugtracker, as what seems to be a bug to you may actually be intended.