Since the Pokemon Munchlax was only introduced in the fourth generation of Pokemon game versions, it is impossible to obtain it in Pokemon Emerald because Emerald came earlier as part of the third generation of Pokemon games. Along with the Munchlax, the fourth generation of Pokemon games introduced 107 new Pokemon species in addition to the 386 existing species in the third generation.
The third generation of Pokemon games came in 2002 with the games Pokemon Ruby and Sapphire for the GameBoy Advance console. Pokemon FireRed and LeafGreen, which were remakes of Pokemon Red and Green games, were also released soon after. The Emerald version was released as an enhanced version of the Pokemon Ruby and Sapphire game.
In 2006, the fourth generation of Pokemon games began with the release of Pokemon Diamond and Pearl for the Nintendo DS console. Other fourth generation games include the versions Platinum and HeartGold and SoulSilver. The fourth generation also saw the incorporation of 3D graphics and the online trading feature for players where they can exchange items and Pokemon.
In the fourth generation games, Munchlax was introduced as the pre-evolved form of the Pokemon Snorlax. Also known as the Big Eater Pokemon, the Munchlax is a Normal type Pokemon with a total base stat of 390. Its abilities are Gluttony and Thick Fat.