6 Summon: Fat Chocobo Wark And Kerplunk Everyone's favorite giant Chocobo, Summon: Fat Chocobo provides a Chocobo token before giving your creatures trample every turn
Sprout Swarm is not a good early game card but it is unlimited gas in a fairly safe way
It can also be quite potent in a Cycling deck like Gavi, Nest Warden, especially if you're cycling for free with a Fluctuator or similar
Tribal Flames A key finisher in Domain Zoo decks, Tribal Flames does 5 damage for 2 mana, which is an awesome rate, even if its only a sorcery
Since October, Ive been running this Doctor Who pairing as my Grixis upkeeps deck
That said, they have some drawbacks you should be aware of: Some weak cards : This is, in part, a side effect of the fact that precons are designed to starting points which players build on: there are some weak cards which are meant to be identified as underperformers and subsequently upgraded