Its second effect is that after it destroys a monster by battle it gains 1500 attack and can attack again which helps in going second or on turn 3
Historically, Decks would use the original three members - "Red", "Green", and "Yellow Gadget" - for constant card advantage and recursion, which was rare at the time
Mega Charizard Y using Charizardite Y
It is a cute mechanic, but the Serpent's stats are nowhere powerful enough to justify a crippling mechanism, and it does highlight how the flavour of the fantasy sometimes needs to be balanced with actual playability
Many kids in the late 90s and early 00s grew up with Pokemon, and this huge pool of people now have earning power, with many of them looking to collect the older card sets they wanted as children but could not afford
All three Forms appear on this card, which gives an impression of a repeating fabric pattern (although a prominent Curly Form Tatsugiri still forms the centerpiece of the image)