CardName: Bilge Rat
Cost: BB
Type: Creature - Rat
Pow/Tgh: 2/1
Rules Text: Sink (Whenever a card is discarded, exile it instead.)
Flavour Text:
Set/Rarity: [Tribute] Azshanir Common
Bilge Rat
C
Creature – Rat
Sink (Whenever a card is discarded, exile it instead.)
Source
I don't get sink.