Now THIS is a very handy little common, albeit like yesterday, pretty Spellcaster exclusive (though being a Beast, I feel like this has some O/FTK potential and use with the Rescue family) Critter (as that name is just insane, so that's what I'm referring to him as) is an Earth attributed Beast, with a low enough attack for level 4 at 1500.  But he's used for his effects.  You can only control one Critter at a time, more on that in a moment.  If you control a Spellcaster, you can Special Summon Critter from your Hand.  During your opponent's End Phase, if this card resides in the Graveyard, you can target and destroy a Monster you control to Special Summon this card.  And THAT is why you can only control one...nuke three of your own Monsters, bring out three of these guys, there's a triple Rank 4...or God knows what else, but this Critter does make XYZ Summoning much easier for Spellcasters.

Rating:  4/5
Art:  4.5/5

So we have this and Thousand Blades as more good Earth options to Rank 4 spam in many decks this week. Nefarious Archfiend Eater of Nefariousness (NAEN or NAEoN I'm going to go with NAEoN.) is a Level 4 Earth Beast-Type monster with 1500 Atk and 200 Def. I'm going to go straight to the effects because the stats are sad. Both effects are Special Summon effects. If you have a face-up Spellcaster on your side of the field, you can Special Summon NAEoN from your hand. If It's in your Graveyard, you can Special Summon NAEoN by destroying some other monster you control during your opponent's End Phase. The only conditions is that you can only control 1 NAEoN.
One combo I want to mention is with Diamond Dire Wolf. Since this is going in some Rank 4 XYZ deck, consider Special Summoning the Performages, Special Summon NAEoN, Special Summon Dire Wolf, and finally use it's effect to destroy NAEoN (Beast-type) and something on the opponent's side of the field.
 
Score: 3/5 It's a good option.
Art: 5/5 I think this is very cute.
-WarlockBlitz

“You keep using that word. I do not think it means what you think it means.” -Inigo Montoya, “The Princess Bride” 

So, let's see just how “Nefarious” this monster really is, shall we? At 1500 ATK and 200 DEF, he's obviously not built for combat. But there are ways you can special summon this guy: if you have a Spellcaster on the field, you can special summon him from hand. Also, if he's in the Grave, you can destroy a monster on your field to resurrect this critter.

I'm not too crazy about the second effect, but the first one's actually really good. If the Spellcaster in question happens to be Level 4, then you can special summon this guy and XYZ them for.... oh, I dunno.... Performage Trapeze Magician, maybe? Or maybe some other awesome Level 4 XYZ monster.

Oh, and look, you're only allowed one of these critters on the field, so it's like they knew that could make for an easy field swarm. Clever, Konami. 

Final Score: 2/5 -Potential is there, but only for Spellcaster-type decks