Ahh, Basking Rootwalla. Aside from the amazingly silly name and picture on him, this guy is really an amazing little creature. For one green mana he's a 1/1 that you can pay one colorless and one green mana to give him +2/+2 until the end of turn (you can only play this ability once per turn). But what really makes him shine is that fact that he has a Madness cost of 0. Madness is an ability that came out in the Torment expansion. Whenever you discard a card with Madness, for any reason, you can play that card for its Madness cost. You can also play this ability whenever it happens, meaning that if you discard a Madness creature during an opponent's turn (when you normally can't play a creature) you can play that creature if you pay its Madness cost. What makes the Rootwalla so good is that he, again, has a Madness of 0, meaning that if he is discarded for ANY reason, you can play him for free.
Zombie Infestation is a nasty little enchantment that came out of Odyssey. It costs a mere one black and one colorless mana, and it allows you to discard any two cards from you hand (any time you want) to put a 2/2 Zombie token into play, which counts as a black creature. A Token is essentially a creature that is not on a card, and comes into play from some other means. It is treated exactly like any other creature, but since it is not on a card, it does not go into the graveyard or into anyone's hand at any point. If anything would put a token into either of those place, the token is just removed from the game.
Wild Mongrel is argued by some to be the best common card EVER printed. For one colorless and one green mana, he's a 2/2. You can discard a card from your hand to give him +1/+1 AND change his color until the end of the turn. He is so amazing because 1) he's fairly undercosted for what he is (a 2/2 for two mana is never a bad deal in the first place), 2) he's incredibly hard to kill because he can "pump" (you can make him bigger by discarding cards), 3) he's invulnerable to things that can't target a certain color (a lot of black cards can just flat out destroy creatures, but the trade off is that they usually can't target other black creatures) because you can change his color at will, and 4) you can basically get any card you want into the graveyard, once he is in play (again, a big theme in Odyssey Block).
Suntail Hawk is simply a 1/1 flying white creature for one white mana.
Ghastly Demise is an example of one of those black cards that I mentioned above. It is an Instant (meaning you can play it any time) for one black mana. It can destroy any non-black creature whose toughness is less than or equal to the number of cards in Ghastly Demise's caster's graveyard. Since Shino's Zombie Cannibal died to Cal's Basking Rootwalla before, there is one card in Shino's graveyard. Since the Suntail Hawk has toughness less than or equal to the number of cards in Shino's graveyard (one), and is not black, Shino can destroy it with Ghastly Demise.
What Dirty Wererat and Gravegouger do is not of importance to understanding what it going on, so I'm not going to talk about that. However, when Shino says that he's "feeding" them to his enchantment, he means that he is discarding them to his Zombie Infestation to generate a Zombie.
When Shino asks Cal if he cares to trade his Mongrel and Rootwalla, he doesn't mean literally. "Trade" is a term used in Magic to describe the situation where one player attacks, the other player blocks, and there is an even loss of creatures. In other words, I attack with 2 creatures, you block with 2 creatures. All 4 creatures die, thus we have "traded."
Cal "pitches" an Acorn Harvest to the Wild Mongrel, meaning that he discards it to give the Mongreal +1/+1 so that it doesn't die to Shino's Zombie token. "Pumping" the Rootwalla just means that he pays the one green and one colorless mana to give it +2/+2 so that it doesn't die to Shino's second Zombie token.
Acorn Harvest is a unique card in that it has an ability called Flashback. If a card with Flashback is in your graveyard, you can play that card just as if it were in your hand, but for its Flashback cost. If Acorn Harvest is in your graveyard, you can pay one green mana, one colorless mana, and 3 life to put two 1/1 green Squirrel tokens into play. If you have played a Flashback card from your graveyard ('Flashed it back') it is removed from the game.
The last thing that I have to mention is that Shino is the second character from Pocket Otaku to make an appearance in FlopJocks. Stay tuned for more cameos...
