You're finishing up a Krenko, Mob Boss deck. You have all of the staples and are at 99 cards and can only add one more of these 4 'fun cards. Which would
Krenko, Mob Boss Commander Deck Guide - Draftsim
Goblins - Krenko Mob Boss - Commander Deck – Crusty Games
Replacement Commanders - SURPRISE! Izzet Another Krenko Deck?! - EDHREC
Krenko, Mob Boss – CustomizedMTG – Magic the Gathering Proxy Cards
Krenko, Mob Boss Commander Deck Guide - Draftsim
Commander Class: Krenko, Mob Boss Deck Tech | FlipSide Gaming