Trans slang for a person who hasn't realized they're trans yet. Usually they show telltale behavior of a trans person despite not knowing, like 'ironically' crossdressing or writing shitty fanfiction about trans people. The word comes from the idea that they haven't "cracked out of their shell", like an egg.
A person who doesn't realize they are transgender yet, or is in denial; an undeveloped transgender person. When they realize, it's referred to as the "egg cracking."
Example: "They've been asking a lot about hormonetherapy, I think they might be an egg."
An egg is a New Zealand slang word for someone who is acting like a dumbass, clown or an idiot. However it is used as a nicer way of saying such things. A recent Kiwi movie called "Boy" uses this word several times. It also could be used instead of saying dick. "stop being a dick, bro"