A redneck call of celebration to anything exciting. Particluarly popular amongst the river folk down in Aintry, Georgia (as depicted in the film "Deliverance"), the phrase is commonly used to cheer on some piggie-squeelin', cornhole action with an unsuspecting canoeist.
Cletus: You ready to squeel like a pig boy?
Jed: Ding dang diggy!!
Ned (piggy): Weeeeeeeeeeeeeeeeeeeeeeeeeee!!!!