well,

Leader might be wrong , since it will only list out name of cats.

Another way (just to simplify m$hacks query)

select name from (

                  -- will give you all the cat names with color=brown 

                 (select name from cat c, animal a where a.color='brown' and a.id=c.id)                

    

                 union

                -- will give you all the dog names with color=brown

                  ( select name from dog d, animal a where a.color='brown' and a.id=d.id)

                 )