ocean
Phytoplankton.
The natural habitat of an orca is somewhere that is cold like the Antarctic or Alaska but sometimes the orca might be seen in cool or warm waters.
An orca would win the battle!
wetlands
The sea.
Grassland
my house
You would find a beaver in the wetlands
Killer whales or "Orca" are a subspecies of dolphins and tend to roam in loose groups called "pods." These groups can range from 3 to 50 Orca, but they roam very lose-like and aren't what I would call a group but more of an area or habitat where they reside.
desert
A moose
Ice and snow