New boss
there is, the boss is here in 1.2
Icon
logo from it
Druid
new Skeleton Witch type, this skeleton type throws at you potions
Butterfly
the mob in 1.0
Moth Larvae
the mob in 1.0, in 1.1 changed his head
items
Owl
the model looks weird, but its cool
Grizzly Bear
a new bear type, will attacks you
Worm
added in 1.1
blocks
Firefly
the newest beta release mob in 1.3
Dragonfly
the new mob in 1.2
Centipede
a new mob source
Snail
the mob in 1.0
MC Icon
logo from minecraft