Each book contains five simple, often humorous, sometimes poignant, short stories chronicling the exploits of a frog and his friend, a toad. Some of their adventures include: attempting to fly a kite, cleaning Toad's messy house as opposed to waiting until "Tomorrow" to do so, and figuring out the ethics of being "Alone".
Frog is taller, with a green shade, and is more friendly and relaxed than Toad; Toad is shorter and stout, with a brown shade and also the more serious and uptight of the duo.
In 2008 three of Arnold Lobel's uncolored, unpublished Frog and Toad books were discovered in an estate sale. They were consolidated into two books and colored by Lobel's daughter Adrianne Lobel; these books appear to be very different from the original set.