Collector Booster Packs often feature exclusive cards, such as special foils, alternate frames, and unique art variants that are not available in regular booster packs
Queen's Bay Soldier: Black bear
I consider Flash to one of those cheat-something-in style cards with Show and Tell, Tinker, Reanimate and co, Oath of Druids, Sneak attack and so on and so forth
The cost reduction applies only to generic mana in the total cost of black spells you cast
The Call for Backup March of the Machine Commander Deck set includes 1 ready-to-play Red-Green-White deck of 100 Magic cards (2 Traditional Foil Legendary cards, 98 nonfoil cards), 10 Planechase cards, 1 six-sided planar die, a 2-card Collector Booster Sample Pack (contains 1 Traditional Foil or nonfoil special treatment card of rarity Rare or higher and 1 Traditional Foil special treatment Common or Uncommon card), 1 Foil-Etched Display Commander (a thick cardstock copy of the commander card with foil etched into the cards border and art), 10 double-sided tokens, 1 deck box (can hold 100 sleeved cards), 1 Life Wheel, 1 strategy insert, and 1 reference card.