A Pokémon egg is an object which every Pokémon hatches from. An egg's shell usually has a pattern reflecting the appearance of the Pokémon inside. Pokémon eggs are produced through breeding.

Eggs of Togepi and Elekid

Some Pokémon, called baby Pokémon, can only be obtained in most games by hatching them from an egg. Legendary Pokémon cannot breed in the Pokémon games and therefore their eggs are only seen in rare situations if at all. Eggs will always hatch into a base evolutionary stage, or in cases such as Marill and Wobbuffet without the proper incense, the stage immediately following a baby stage.

In the games

Pokémon Snap

The first appearance of eggs in the Pokémon video games was in Pokémon Snap. In this game, the Eggs of the three legendary birds can be found and hatched.

Eggs available

Articuno
This egg is in the Cave area. It is silver and has a crystalline form. It hatches with the aid of two dancing Jynx.
Zapdos
This egg is in the Tunnel area. It is yellow with a jagged electric pattern on it. It hatches with the aid of a Pikachu's Thunderbolt.
Moltres
This egg is in the Volcano area. It is yellow with a red flame design on it. It hatches when a Pester Ball knocks it into the lava.

Generation II

Pokémon Gold and Silver were the first games in which eggs and Pokémon breeding became a notable part of the system. In this game, an egg can be produced by two Pokémon at a Pokémon Daycare, which is then given to the player upon their next visit. This egg is carried in the player's party until they take a certain number of steps and the egg hatches. The number of steps required for an egg to hatch varies with the Pokémon species inside the egg.

All Generation II eggs appear as a yellow egg with dark spots.

Eggs available

This excludes any eggs which the player can breed themselves.

Pokémon Gold and Silver / Pokémon Crystal
A Togepi egg is given by Mr. Pokémon, who lives on Route 30.
Pokémon Crystal
The Old Man at the Pokémon Daycare gives an egg. It can hatch into Pichu, Cleffa, Igglybuff, Tyrogue, Magby, Smoochum, or Elekid. It will know Dizzy Punch and has a 50% chance of being shiny.

Generation III

In the third generation games, Pokémon eggs are the same as in the second generation games.

All Generation III eggs appear as a gold-colored egg with green spots. This is an updated sprite of the Generation II egg.

Eggs available

This excludes any eggs which the player can breed themselves.

Pokémon Ruby and Sapphire / Pokémon Emerald
A Wynaut egg is given by an old couple in Lavaridge Town.
Pokémon FireRed and LeafGreen
A Togepi egg is given by an old man on Chrono Island.

Abilities

Pokémon Emerald adds two Abilities which affect egg hatching.

If an egg is in the same party as a Pokémon with either of these abilities, the steps needed to hatch an egg will be halved.

Generation IV

In the fourth generation games, Pokémon eggs are the same as in the second generation games.

Most Generation IV eggs appear as a cream-colored egg with green spots. This is a new sprite based off the same egg design used in Generation III.

Manaphy, however, hatches from a unique clear blue egg with a red center and a ring of white spots. This egg can be obtained through a special mission in Pokémon Ranger and transferred to Pokémon Diamond and Pearl where it will hatch into the legendary Pokémon.

In the anime

File:PokemonEggsAnime.jpg
A breeding house in the anime, full of different Pokémon eggs

Pokémon raised from eggs

Misty's Togepi
This egg was white with blue and red triangular spots. It was found by Ash deep in Grandpa Canyon in Attack of the Prehistoric Pokémon. It was taken care of by Brock and, for a short period, by Meowth. It hatched into a Togepi in Who Gets to Keep Togepi?. Since Misty was the first person it saw, the baby Pokémon thought she was its mother, and thus became hers.
Ash's Phanpy
This egg was light blue with no designs. It was given to Ash as a prize for winning a race in Extreme Pokémon!. He took care of it himself, and it hatched into a Phanpy in Hatching a Plan!.
Ash's Larvitar
This egg was light green with no designs. It was given to Ash in Lapras of Luxury. It hatched into a Larvitar in Hatch Me If You Can!.
May's Eevee
This egg was brown with a light brown stripe of diamonds around its middle. It was given to May by a day-care worker in May's Egg-Cellent Adventure. She took care of it herself, and it hatched into an Eevee in Time-Warp Heals All Wounds.
Manaphy
This egg was clear blue with white spots and a red center. It was primary to the plot of Pokémon Ranger and the Temple of the Sea. During the movie, May took care of it and it hatched into a Manaphy.