How is "e.g." pluralized?

Since e.g., translated from the Latin, means "for example," it doesn't need a plural.

Of course you might need to pluralize "e.g.," if you are talking about the abbreviation itself. For example, "In this document we have too many i.e.'s and e.g.'s."

As shown, I would add an apostrophe + 's' for the same reason needed in the expression "She earned all A's and B's." Something is needed to clarify that the 's' in question is not part of the abbreviation.

It says here in this book: Latin second declension neuter: exemplum singular; and exempla plural: example, sample, or model.

And the neuter singular adjective gratum, plural grata: pleasing, grateful.

So e.g. might mean: Thank God! I've finally found some real-world agreement.

I hope that I shall ever see no peoples using e.e.g. --JKilmer

The E.G. part stands for Exemplī Gratiā. This is the Latin way of saying what we say in English as "for the sake of example".

Note that English uses a lot of little words that Latin doesn't. This is because Latin is inflected while English isn't. English still has a plural for nouns, but no cases. Latin has singular and plural, but also five cases.

To take the Latin phrase apart, Exemplī is the possessive (genitive) singular form of the noun exemplum 'example', so in Latin it means "of example". Literally.

And Gratiā is the ablative singular form of the noun gratia 'benefit; sake', so in Latin it means 'for the sake'. Literally.

If you want to pluralize the phrase, you have to decide which noun to pluralize -- is there more than one example, or more than one benefit? Since you're looking for multiple examples, one would use the plural genitive exemplōrum 'of examples', instead of the singular genitive exemplī of example'.

I.e, it should be Exemplōrum Gratiā instead of Exemplī Gratiā. Of course, that would still be e.g.