Dragon Egg is one of those cards players keep asking about. Here is, in plain words, what its official text says, the rulings published by Wizards of the Coast, and the combos players actually run.

Official card text

Defender When this creature dies, create a 2/2 red Dragon creature token with flying and ": This token gets +1/+0 until end of turn."

How it works : Dragon Egg

Original English text — Wizards of the Coast / Scryfall

No additional ruling has been published for this card.

Interactions with other cards

These cards' text mentions Dragon Egg.

Nesting Dragon

Flying Landfall — Whenever a land you control enters, create a 0/2 red Dragon Egg creature token with defender and "When this token dies, create a 2/2 red Dragon creature token with flying and '{R}: This token gets +1/+0 until end of turn.'"