Mishra's Bauble, one of the best eggs in Magic, isnt as broken, but being a 0-mana cantrip (even if the card draw is delayed) makes it a mainstay in Vintage and Modern
Sometimes you wont kill your opponent in one, so the tokens can attack for more sustained damage over multiple turns or even defend so that you can combo off on a later turn
Other times, it's worth pursuing for the surprise factor alone
The number of packs in a booster box depends on the TCG, but here are the examples from some of the most popular trading card games on the market now
Here's how: Pull Rate : The rarer the card, the harder it is to pull
C Common UR Ultra Rare Cyber Shadow Gardna X TRAP Continuous During your opponent's Main Phase: Special Summon this card as an Effect Monster (Machine/EARTH/Level 4/ATK ?/DEF ?)