Cannot attack directly. If this card is banished: You can Special Summon this card, and if you do, this card gains 200 ATK for each of your banished Dinosaur monsters. You can only use this effect of "Giant Rex" once per turn.
While face-up on the field, this card cannot be banished. Each time a Dinosaur-Type monster(s) is sent to your Graveyard, place 2 counters on this card. You can Tribute this card; Special Summon 1 Dinosaur-Type monster from your Deck whose Level is less than or equal to the number of counters that were on this card.
Target 1 Dinosaur-Type monster you control; equip this card to that target. It gains 1000 ATK. When it destroys an opponent's monster by battle and sends it to the Graveyard: The equipped monster can make a second attack on an opponent's monster in a row.
I notice something. Well I could be wrong. It seems in compliance of players complaining of their stupid drop rate (which they are), konami made it such a way that drop rate is higher on first day and last 2 days of events.