Blubber
Yes.
Walrus
Walrus are mammals.
walrus seal
a walrus
walrus have tusks and seals don't
Seal and Walrus Hunting - 1910 was released on: USA: 3 January 1910
a big fat walrus
It has blubber
The blubber protects the walrus from the cold.
Walrus is the largest seal in the world. So yes, it is.
The 'stuff' could be the thick layer of blubber (fat) that protects the walrus from the cold.