Great Pyrenees enjoy a reputation as being excellent companions and they are known for behaving themselves with kids and cats. 

Our cats bristle at the sight of any dog or another cat, but from the day we brought Lilly home, Puff and Pooh "tolerated" Lilly.  I won't go as far as to say it was love at first sight, but after a short get-acquainted period, these animals now share the same space on the floor and the never fight.  Lilly will occasionally chase one of the cats, but it is all in fun and on the few occasions she actually cornered a cat, she merely stands over it as if protecting it.