I will use Bobbyphills system of rating cards to compare Charizard and
Ninetales.

HP:
Ninetales:   80/Stage 1
Charizard: 120/Stage 2

Ninetales: 12
Charizard: 20

Retreat cost:
Ninetales: 1
Charizard: 3

Ninetales: 20
Charizard: 23

Attacks and PP
Ninetales: Lure: CC: Switch the Defending pokemon with a benched pokemon
Fire Blast: RRRR: 80: Discard 1 Energy from Ninetales
Charizard: Pokemon Power: Energy Burn: Turn all energy attached to Charizard
into R energy, cannot be used if Charizard is Confused, Asleep, or Paralyzed
Fire Spin: RRRR: 100: discard 2 energy from Charizard

Well in my opinion, Charizard's attacks and PP get a 5 and Ninetales' Attack
ans PP get a 4.

Ninetales: 46
Charizard: 53

Speed:
Ninetales' smaller stage Vulpix's only attack is worth 2 fire Energy.
Ninetales's First attack is for 2 colorless energy. His Fire Blast is worth 4
Fire Energy

Charizard's smallest stage Charmander's first attack is for 1 colorless
energy, his second attack is worth 1 Fire and 1 colorless. Charmeleon's first
attack is woth 3 colorless energy. His second attack is worth 2 Fire and 1
colorless. Charizard's only attack is worth 4 colorless energy(Thanx to
Energy burn)

Ninetales: 62
Charizard: 69

Versatility
Weakness: Both have weakness to water

Ninetales: 68
Charizard: 72

Resistance
Ninetales: None
Charizard: Fighting

Ninetales: 68
Charizard: 87

Color
Ninetales: Fire
Charizard: Colorless(Yes this may sound wierd but Charizard's energy burn
makes it a colorless, Charmander and Charmeleon are Fire type but Charizard
can use any energy, does 100 damage and all pokemon with a weakness to Fire
have 100 HP or less so Charizard is going to kill it in one hit anyway

Ninetales: 74
Charizard: 96

Ninetales: 7.4
Charizard: 9.6
(This is in my opinion)
Email me at Aerodacty13@aol.com