It contains five preconstructed decks (one for each color) plus accessories needed to play the game (spindown life counters, life counter platforms, +1/+1 counters, and five reference cards)
Honorable Mention: Yuriko, the Tigers Shadow While neither a rat nor directly synergistic with rats, Yuriko, the Tiger's Shadow does have commander ninjutsu, and theyre both one of the best Dimir commanders, and one of the best aggro commanders
It's very defensive in nature and stronger in grind games, attempting to gather as many resources as it can for a big attack at the end, mainly through the trap "Melffy Playhouse", which can return most of your opponent's field to the hand and increase your Xyz Monsters' ATK to ludicrous levels for a final OTK
It is a pure construction with no quirks