It's kind of fun - I go to the member list - search members - and type in the word - and see what comes up.
I would guess that there are LOTS of people who have some version of 'grandmother' in their screen name.
More animals -
bird - 170
dog's mom - 0
pup - 49
zebra - 5
rhino - 0
alligator - 0
crocodile - 0
beast - 3
lamb - 33
ferret - 2
llama - 14