http://puremtgo.com/articles/booshs-combo-compendium-vol-1


So this deck uses Imagecrafter, Unnatural Selection, & Amoeboid Changeling to change creatures' types for various fun, effective, and silly things to happen. I tried to make it so that a lot of the cards interacted with each other enough that if for some reason you didn't snag one of your 12 creature-type-changers your deck wouldn't be useless. You could always stack your deck with 4 Mistform Mutant to increase your type-changer count to 16, but I decided that the mutant was too expensive, mana-cost-wise, so I didn't include it.
Knight of the Mists: Card text: When Knight of the Mists comes into play, you may pay . If you don't, destroy target Knight and it can't be regenerated. Don't pay the ; pay  instead for your Unnatural Selection, change your opponent's Massacre Wurm into a Knight, and hose it.
Rashida Scalebane: Change your opponent's various attackers or blockers into dragons, and use Rashida to hose them and gain some life. Another fun interaction is destroying your own dragon tokens made by Utvara Hellkite to gain some life in a pinch.
Kinsbaile Cavalier: Change any creature you want into a knight to give them double strike. Automatically gives Amoeboid Changeling, Knight Exemplar & Knight of the Mists double strike.
Knight Exemplar: Change any creature you want into a knight to make them indestructible. Automatically makes Amoeboid Changeling, Kinsbaile Cavalier & Knight of the Mists indestructible.
Spirit Mirror: Combo is listed above. Dastardly.
Ancestor's Prophet: If you have out no other clerics, at least the prophet is one so you only need to change 4 other creatures into clerics to tap them all for 10 life. If you use Unnatural Selection solely, it's 4 colorless mana to gain 10 life. Holy Justiciar, Amoeboid Changeling & Undead Slayer are already clerics without fancy tricks.
Holy Justiciar: Without fancy creature-change tricks, this can still be activated to at least tap-down opposing threats. If you happen to alter an opposing creature's type to zombie, you'll get to exile the creature for .
Undead Slayer: Change an opposing creature's type to zombie, skeleton or vampire and exile them for only . Since Holy Justiciar provides the tap-down ability if there's no creature-change tricks to be had, I included more of them in the deck than Undead Slayer.
Siege-Gang Commander: Twofold reason for inclusion: provides goblin tokens that you can change into various creatures for various effects (change em all into clerics to gain life, etc) & allows you to sacrifice goblins for 2 damage a clip-- so you can either sac the tokens and itself, or change your various creatures into goblins to sacrifice for damage in a pinch.
Utvara Hellkite: turn any creature you control into a dragon before you attack so you can score some free dragon tokens. A great way to use this would be to have out Unnatural Selection. Plan to attack with your goblin token from Siege-Gang Commander and pay  to change it into a dragon before it attacks. After it attacks and the dragon-token-makin' trigger occurs on the stack, pay  again and change it into a knight if Knight Exemplar is out thus making the goblin-dragon-knight indestructible so it lives through combat and you can pull off this trick again next combat. Amoeboid Changeling also already counts as a dragon and a knight, so if both Utvara and the Exemplar are out, you can just attack with it.
Goatnapper: Tap Imagecrafter, make your opponent's Archon of Justice into a goat, cast Goatnapper and steal the Archon-of-Goat-Justice for a turn. Maybe tap Amoeboid Changeling to make the stolen Archon into a goblin, and sacrifice it to Siege-Gang Commander for hilarious results. Goatnapper itself is a goblin, and can be sac'ed to Siege-Gang Commander.
Muddle the Mixture: Counter a pesky sorcery or instant, or, Transmute it to find Unnatural Selection or Amoeboid Changeling--major combo pieces.
Sideboard: The sideboard contains more Goatnappers and Knight Exemplars which you already know function pretty well in this deck, but it contains a mini Sliver theme, since you can change your creatures into slivers if need be. Homing Sliver, like Muddle the Mixture, can be employed to search out Amoeboid Changeling. It also has 2x Enlightened Tutor in order to help you snag your Unnatural Selection or Spirit Mirror.