The phrase "everybody and his dog" is commonly used to describe a situation where a large number of people or things are present. Synonyms for this phrase include "everyone and their grandmother," "all and sundry," "the masses," and "the whole world and his uncle." These phrases are often used in informal or conversational settings, and they emphasize the abundance or multitude of people or things in a given situation. When searching for alternatives to "everybody and his dog," it's important to consider context and tone, as different phrases may be more or less appropriate depending on the subject matter and audience.