Smugleaf 

The fan nickname for Snivy, a fictional species from the Pokémon franchise that made its debut in the 2010/2011 Nintendo DS video games Pokémon Black Version and Pokémon White Version as Pokémon species #495, serving as the Grass-type starter Pokémon for the Unova region.

This leaf-tailed Pokémon quickly gained significant popularity on the Internet for its smug looks, hence the nickname. It's been called at times, "the new Mudkip", and "Smugleaf" became a sort of Pokémon variation of trollface. There were also references made about its design being similar to that of "Excalibur" from the popular anime series, Soul Eater.

Smugleaf says, "U mad?"

Smugleaf by Just Another Anonymous Person November 26, 2010

Smugleaf 

The Grass Type Generation V Pokemon. It's not its officical English name, yet it has recieved the name Smugleaf due to it's appearance having a half-closed eye and a smirk. Due to it's popularity building on 4chan, it has bascically become the new Mudkip.

Internet user 1: "So I herd u like Smugleafs

Internet user 2: "Don't you mean Mudkipz?"

Internet user 1: "Not anymore"

Smugleaf by viva riolu May 18, 2010

Smugleaf 

The greatest starter pokemon in the universe. Best meme ever too.

You just made square pancakes?
Smugleaf made some that look like pikachu.

Smugleaf by hOI!!!!! February 10, 2017