Spider-Punk is only useful to other players if they are able to play another turn, so setting up a combo as early as possible can make sure the game ends with that strategy
Every time one of your dragons attacks, you get to tap down a nonland permanent your opponent controlsand it stays tapped through their next untap step
Anzrag is also an 8/4, meaning either your opponents are looking more than a third of their life total if they take the hit, or theyre going to be subject to another smacking
Thankfully, there really aren't a ton of "lose life" cards in Standard, at least ones that see much play
Both of these halves are good enough to play and getting both of them for one card is good value and this will come in handy in a lot of Simic decks
Green with Garruk, Caller of Beasts or Yeva, Nature's Herald