Phrases and their definitions straight from a real live cowboy...

The engine's runnin' but ain't nobody driving.
(Not overly intelligent)

All hat, no cattle.
(All talk and no action)

We've howdied but we ain't shook yet.
(We've made a brief acquaintance, but not been formally introduced)

He's got tongue enough for 10 rows of teeth.
(Talks a lot)

He looks like the dog's been keepin' him under the porch.
(Not the most handsome of men)

As full of wind as a corn-eating horse.
(Prone to boasting)

You can put your boots in the oven, but that don't make 'em biscuits.
(You can say whatever you want about something, but that doesn't change what it is.)