Oh hai worse Craw Wurm! How are you doing today worse Craw Wurm? Seriously, this thing is BAD. Let's break it down and find out why it's a bad card. We'll use this as a class on card development!
First, the Power to Converted Mana Cost (CMC) ratio. A 1:1 ratio such as the case for this card (6 power to 6 CMC) is fine. Cards like Sea Monster and Archwing Dragon also pass this test since they too have a 1:1 ratio. Some cards, like Ball Lightning have a 2:1 or greater ratio and are seen as great since they provide more bang for your buck as it were.
Second, what are its abilities? For an uncommon, we don't want there to be too many abilities, but it has to be worth the 6 mana to play. Giving it haste is great, especially since it's in red. However, this thing has no evasion of any type, meaning that it can easily be blocked by Ted. Still, this is a slight step up from Craw Wurm since Craw Wurm can't attack when it comes out.
Finally, what are the drawbacks of the card, if any? Viashino Cutthroat, for example, has to bounce to your hand each turn. Ball Lightning dies at the end of turn. This thing... blows up two of your lands. Why?! This card has sudden;y been downgraded from "better Craw Wurm" to "worse Ball Lightning that costs twice as much" since no one in their right mind will pay the echo cost to keep this bucket of sadness around.
Pros: Faster than Craw Wurm for same price
Cons: Blows up 2 of your lands, no evasion