Penguin suit 

A dinner jacket or tuxedo.

Because the wearer looks like a penguin in it. Simples.

I need to hire a penguin suit for the wedding.

Penguin suit by rodinuk July 26, 2010

two penguins in a suit 

Often confused with two chickens in some pants, it is in fact two penguins- Topsy and Bertram- in a suit, also known as (aka) the mod Avid Spark

Gamer 1: What's up with that mod?
Gamer 2: He's two penguins in a suit.
Gamer 1: Oh, that explains it.

two penguins in a suit by Notintoracism December 20, 2010