Since Johto came out all those years ago I have heard that people say they are "Cats" or "Dogs" like how Articuno, Moltres and Zapdos are legendary birds.
I've given you the option of voting for "Cats", "Dogs" and "Other" and if you choose "Other" please specify what you think they are.
Hopefully this thread can settle an argument (however I doubt it) about this silly topic.
My opinion: They are Legendary Cats. Entei could be mistaken for a cat and Raikou is obviosly feline - just look at it. But Suicune, to me it just looks like..a thing! I just don't really see much dog in this bunch, except maybe for Entei.