Eastern Spadefoot Toad
Scaphiopus holbrookii holbrookii

Description:
Reaches a length of 2.75".  Skin greenish to brown and covered with warts, many of which are tipped with orange.  Each hind foot has a hard, black, crescent-shaped spade located at the heel. Large brassy eyes with vertical pupils.  
Similar Species:
True toads (genus Bufo ) have horizontal pupils.

Eastern Narrow-mouthed Toad
Gastrophryne carolinensis

Description:
Ranges from 0.8" to 1.25".  Body color is black to dark gray.  Snout is pointed and there is a fold of skin across the back of the head just behind the eyes. Legs are short and stubby.
Similar Species:
Toads of the genus Bufo have warty skin and lack of fold of skin across the back of head.

Oak Toad
Bufo quercicus

Description:
Small (up to 1.5"), warty skinned toad with yellow to orange stripe down center of back and 3 to 4 paired spots on back.
Similar Species:
Young southern toads have a large bony ridge between their eyes.  Oak toads have round rather than kidney-shaped parotoid glands.