When Parasite is turned face-up it gives you a combat trick as its triggered ability, which helps you win a lot of early- to mid-game combats
However, if a permanent has multiple card types, it may be chosen as the target for more than one instance of the word "target." For example, you could cast Decimate targeting an artifact creature, an enchantment, and a land
Casting two spells is trivial for Spellslinger decks, where cantrips like Gitaxian Probe are commonplace, so this can easily draw you a card per turn
Getting this Wurm into play with Sneak Attack or Through the Breach means you attack for 15 trample and you get to keep three baby Wurms
The potential to have these micro-sets appear to freshen things up in-between larger sets is a fun one
Faerie Mastermind can do more than its fair share as it leeches off of multiple opponents, too