The overtext below is true.
The overtext above is false.
1 Infernal Spawn of Infernal Spawn of Evil (Unhinged)
2 Ravenous Rats
1 Carrion Rats
1 Crypt Rats
14 Relentless Rats
2 __________ (Unhinged)
1 Nezumi Shortfang
2 Drain Life
1 Kill! Destroy! (Unhinged)
1 Lab Rats
1 Intruder Alarm
1 Oversold Cemetary
2 Urza's Hot Tub (Unhinged)
2 Soul Foundry
1 Sol Ring
1 Crucible of Worlds
2 Grim Reminder
4 Snow-Covered Swamp
4 Snow-Covered Islands
1 Strip mine
OK, it should be fairly obvious that this isn't a tournament-legal deck. It also isn't as tough as it could be... 2 more hot tubs and maybe some extra mana will be enough to make this extremely annoying; too annoying for my playing circle!
Anyway, there is some good synergy in here... let's start with Urza's hot tub;
1. Whenever you use it, if you have 2 mana spare, that's 2 points of direct damage from Infernal Spawn^2, and no spell cast, so very unlikely to be countered.
2. If you have ______ then you can effectively pay 3 mana for any card you want.
3. If you get Cricible of Worlds, you can discard a land for a land, then play the discarded land from the graveyard
4. If you want ______ then you can effectively pay 3 mana for it, and discard any card.
5. Late in the game, you can discard rats for more rats, then pop the discarded card back to your hand with Oversold Cemetary.
6. Need some blue mana? 2 mana swaps a swamp for a snow-covered swamp, 2 mana swaps a snow-covered swamp for a snow-covered island.
OK, on to _______, 1 mana lets you rename this beastie to any name you like, so it works very well with the hot tub, but also with Grim Reminder. Get Grim Reminder, and you can do your opponent 6 damage for 4 mana when he/she casts any spell (or 6 mana for 8 damage with Infernal Spawn^2). Also, if you feel the need to cast _______ for some reason, it can counts as a Relentless Rat.
Finally one other nice combination... Marrow-Gnawer + Intruder Alarm gets you infinite relentless rats, heh heh. Very low probability of this coming up, unless you abuse the hot tubs.
Finally finally, note that most of the combinations would work in any other deck, not just the rat deck.
I'd be interested in any other nice combinations that can be squeezed in here; not interested in a killer deck, but I am interested in lots of surprises