The name should not be taken literally since similar to most adages, this is simply a name christened to unique conceptualized meals that the English have developed. And for the sake of clearing things out, no frogs or toads are included in it!
Seriously, it is simple egg and toast presented in a unique way. The center portion of bread is simply cut using a round object such as a cookie or a glass and then placed in a frying pan to which eggs are placed in the revealing circular portion. It is like simply frying an egg sunny side up but with borders which produces an appealing manner of presentation for dishes originating from England.
While the name termed for it may need some work, it is commonly known as Egg in the Basket as well. But knowing how to stimulate the curiosity of most people, the attention garnered by Toad in a Hole will really catch their interest since they are not too familiar with such an offered English meal.