Half of a Hero's health would be rounded down if the health is an odd number. For instance, if a Hero has 11 health, the Hero would have to have taken at least 6 damage before entering this Room in order to get the +2 bonus.
A card best built as the first card in the dungeon (in other words, being the last room in the dungeon). This card is good against Heroes that would otherwise make it through to the Boss, especially Epic Heroes, if other powerful rooms are built ahead of this room.
The cards effect is a reference to the fact that sharks can smell blood in water and are more likely to attack bleeding victims.
Even though the card was released as a Kickstarter Exclusive, it was created during the games pre-alpha stage.