Mewtwo (Super Smash Bros. Melee)

Origins
Mewtwo made his debut in 1996, on the Pokemon series. He was known as "Pokemon #150", and was caught only after beating the game, in the Unknown Dungeon next to Cerulean City. He has also starred in his own movie, providing his backstory as the genetic clone of Mew.

Pros

 * Superb recovery, vertical and horizontal
 * Good grabs
 * Great wavedash

Cons

 * Too easy to KO
 * Considered worst character in SSBM and is at the bottom of the tiers list
 * Very big target with seemingly nothing to compensate for it. His tail is also a hitbox which makes Mewtwo a bigger target in the air.
 * Requires a lot of mindgames in order to effectively play Mewtwo and a deep understanding in the opponent's character and Mewtwo's mediocre moveset.

Metagame and Tier Ranking
Mewtwo is considered, played at the highest Metagame, the worst character. He is number 26 on the tier list, ranked at the bottom. One of his only redeeming qualities is his godly recovery, however this is easily negated by his ability to be KO'd in very low percentages.

Overview
Fair warning, there is a lot of jargon in this section. If you don't understand what it means please refer to the Terminology section.

Taunt

 * Total Frames: 120
 * HMHMHMHMHMH!: 1

Jump

 * Frame Data:
 * airborne on frame 6
 * Air time: 60
 * Earliest FF: 31
 * FF air time: 44
 * SH air time: 35
 * Earliest FF: 20
 * SH FF air time: 24
 * For maximum height gain from M2's 2nd jump, you should interrupt it with an attack on frame 34. Frame 33 is only SLIGTLY less, and performance drops equally from too soon or too late, within a few frames.
 * 2nd jump earliest FF (no moves): 48

Air Dodge

 * Really small: 1-3, 30-33
 * Invincible: 4-29
 * Total Frames: 39

Ground Dodge

 * Invulnerable 2-21 out of 37

Roll

 * Invulnerable 4-19 out of 37

Landing Lag

 * 4 frames

Dash

 * Dash becomes run at frame 19
 * Turn-jump Threshold: 22
 * Run turnaround: 37

Ledge Properties

 * Ledge stand <100%
 * Total: 33
 * Invincible: 1-30
 * Ledge stand 100%>
 * Total: 59
 * Invincible: 1-55
 * Ledge roll <100%
 * Total: 49
 * Invincible: 1-27
 * Ledge roll 100%>
 * Total: 79
 * Invincible: 1-74
 * Ledge attack <100%
 * Total: 55
 * Invulnerable: 1-22
 * Hit: 26-30
 * Ledge attack 100%>
 * Total: 69
 * Invulnerable: 1-46
 * Hit: 50-52
 * Ledge jump <100%
 * Total: 52
 * Invulnerable: 1-15
 * Soonest FF: 46
 * Ledge jump 100%>
 * Total: 67
 * Invincible: 1-21
 * Soonest FF: 52

Neutral A

 * 3-6%
 * http://img206.imageshack.us/img206/2462/jabs13gp.gif
 * Frame Data:
 * Total: 29
 * Hit: 8
 * Window of the Dark Flame: 3-28
 * Dark Flame starts: 12 (or later)
 * Dark flame delayed by 1 frame

Rapid A

 * 1-2%
 * Frame Data:
 * Total: 79
 * Hit: 13, 20, 27, 34, 41, 48, 55, 65

Dash A

 * 3-9%
 * Frame Data:
 * Total: 49
 * Hit: 10-29
 * IASA: 38

F-Tilt

 * 2-10%
 * Normal
 * http://img206.imageshack.us/img206/1165/ftilt11wd.gif
 * Angled down
 * http://img206.imageshack.us/img206/7792/dftilt4xj.gif
 * Angled up
 * http://img489.imageshack.us/img489/3940/uftilt5gw.gif
 * Frame Data:
 * Total: 31
 * Hit: 6-8
 * IASA: 29

Up Tilt

 * 2-10%
 * http://img489.imageshack.us/img489/4141/utilt11wt.gif
 * Frame Data:
 * Total: 31
 * Hit: 6-11
 * IASA: 28

D-Tilt 2-9%

 * http://img206.imageshack.us/img206/3002/dtilt12ka.gif
 * Frame Data:
 * Total: 29
 * Hit: 5-7

Forward Smash

 * 6-27%
 * Frame Data:
 * Total: 59
 * Hit: 18-19
 * Charge Frame: 14
 * IASA: 52

Down Smash

 * 8-20%
 * Frame Data:
 * Total: 59
 * Hit: 20-21
 * Charge frame: 17
 * IASA: 38

Up Smash

 * 1-20%
 * Frame Data:
 * Total: 79
 * Hit: 9-10, 13-14, 17-18, 21-22,
 * 25-26, 29-30, 33-34
 * Charge frame: 2
 * IASA: 70

Aerial A (nair)

 * 1-16%
 * http://img203.imageshack.us/img203/2142/nair10cp.gif
 * Frame Data:
 * Total: 54
 * Hit: 5-6, 9-10, 13-14, 17-18, 21-22,
 * 25-26, 29-30, 33-34, 37-38
 * IASA: 42
 * Auto cancel:
 * Landing during move has 1 frame of damage
 * Landlag: 26
 * Lcanceled: 13

Aerial Forward A (fair)

 * 7-14%
 * http://img203.imageshack.us/img203/7352/fair14ei.gif
 * Frame Data:
 * Total: 39
 * Hit: 5-7
 * IASA: 36
 * Auto cancel: 35>
 * Landlag: 25
 * Lcanceled: 12

Aerial Back A (bair)

 * 4-13%
 * http://img204.imageshack.us/img204/204/bair16qj.gif
 * Frame Data:
 * Total: 31
 * Hit: 12-15
 * Auto cancel:
 * Landlag: 28
 * Lcanceled: 14

Aerial Up A (uair)

 * 5-12%
 * http://img472.imageshack.us/img472/9544/uair10pv.gif
 * Frame Data:
 * Total: 37
 * Hit: 9-11
 * IASA: 35
 * Auto cancel:
 * Landlag: 20
 * Lcanceled: 10

Aerial Down A (dair)

 * 7-16%
 * http://img204.imageshack.us/img204/4493/dair19sc.gif
 * Frame Data:
 * Total: 57
 * Hit: 18-21
 * IASA: 47
 * Auto cancel:
 * Landlag: 28
 * Lcanceled: 14

Grab and Throws
Mewtwo has the 12th best grab range, and his grabbing speed is 7 frames which is the same as Sheik's.

Standing Grab

 * Total: 30
 * Grab: 7-8

Running grab

 * Total: 40
 * Grab: 9-10

Throws

 * Grab Attack 1-3%
 * Forward Throw 1-8% (About 20% if done facing a wall)
 * Back Throw 6-11%
 * Up Throw 6-17%
 * Down Throw 6-17%

Shadowball
with damage
 * Uncharged 2%
 * Full Charged 25%
 * Frame Data:
 * Starts charging: 18
 * Full charge achieved at frame 119
 * When charging, does first 2 frames of damage, then loops 2 no damage and 3
 * Rolling while charging starts ASAP
 * L/R to stop charging: 8 frames lag
 * Shot from charging
 * Total: 24
 * Comes out on frame 9
 * Shot from full
 * Total: 41
 * Comes out on frame 26
 * Shadow Ball lasts 69 frames

Confusion

 * 10%
 * Frame Data:
 * Total: 55
 * Grab: 12-15
 * Reflect: 12-38

Disable

 * 1%
 * Total: 39
 * Eye spark comes out: 15
 * Eye spark lasts 7 frames

Teleport

 * N/A
 * Frame Data:
 * Total (ends in air): 32
 * Invincible: 8-17
 * Total (ends on ground): 46
 * Landlag: 30
 * Landfallspeciallag: 4

Terminology Index
frame when it arrives. according to the character's maximum running speed, and is assuming you keep holding the stick in the direction of the turn. When a character is running and they turn around to dash in the other direction, they can interrupt the turning animation with a jump. The turn-jump threshold frame is the first frame of the turn in which the character will be facing the way they came.
 * Advantage
 * This combines shield stun, hit lag, and the remaining duration of the attack into a number. It shows how fast you can act after finishing your attack as opposed to your opponent acting after the shield stun. For aerial attacks, this shows as if you hit with the attack the very frame before landing. Shown here, your opponent can act 10 frames before you can, albeit from a shield.
 * NOTE: not all Advantage numbers are 100% accurate. If you hit with an attack 1 frame later, you will gain 1 frame advantage, there's no telling exactly which frame you'll hit on for every attack. I've tried to show both ends of the possibility spectrum for attacks that have a large hit window.
 * ANOTHER NOTE: Sometimes there are attacks that can be quickly be done in succession (mostly rapid A ones), which have a different advantage than waiting for the move to finish and do a totally different move. In this case, the advantage number shows how fast your followup attack will have a hitbox out.
 * Air time
 * Total time your character is in the air from their first jump, assuming no attacks.
 * Auto cancel
 * Landing during an air attack such that your character goes into their standard landing animation instead of the animation for whatever attack they were doing.
 * Charge frame
 * When charging a smash attack, this is the frame during which your character flashes in place. When you release A, your character holds the pose for 1 additional frame. You can charge for 60 frames max.
 * Earliest FF
 * If you press down on or after this frame, you will fast fall. There is a short window (3 frames) before this during which you may begin holding down, and you will fastfall on this
 * FF air time
 * The time your character will be in the air with immediate fast falling.
 * Hit
 * examples 12, 14-16
 * Frames during which there's a hitbox. The same hitbox can't hit the same opponent more than once. For B moves, I may describe the hitboxes.
 * IASA
 * Interruptible As Soon As. You can do an attack, jump, dash, turn, crouch, or shield on the IASA frame. You can interrupt with B moves on the ground only.
 * Jump: airborne on frame X
 * This is the first frame you are truly in the air, and you can begin attacks on this frame. To short hop, you must be holding jump for no longer than X-2 frames.
 * Landfallspeciallag
 * After most up Bs and some other Bs, you fall flashing black and can't do anything. This number shows the real lag you get upon landing.
 * Landlag
 * For A air attacks, this shows the lag time of that attack if you land while doing it. For B attacks, it shows the lag you get if you land while doing it, but only if it actually gives you a landing animation, as opposed to some B attacks that simply continue the animation on the ground.
 * Lcanceled
 * The lag time of an air attack when L cancelled.
 * Ledge Thingies (don't you just love this one?)
 * For ledge jumps, the character leaving the ledge and the invincibility running out coincide. For other ledge thingies, the character uses the ledge for the duration of the animation, unless it is interrupted.
 * Run turnaround
 * The time your character takes to turn around while running. You can jump out of this, but nothing else can cancel it. It can vary, depending on your momentum. The number given is
 * SAF
 * Soonest Actionable Frame. The first frame of any move during which you can do anything else. Like IASA, only also applicable to noninterruptible moves. This might be replacing IASA.
 * Shield hit lag
 * This is how many frames your attack freezes in place while hitting your opponent's shield (or them).
 * Shield Stun
 * If your opponent shields this attack, this is how many frames they are in shield stun. The first frame of their shield getting hit doesn't count, because they could have jumped or dodged or rolled on that frame, so they can't really be said to be in stun.
 * Total
 * The total duration of the attack. If the total is 30, you are stuck doing that attack for 30 frames. Frame 1 is the frame you pushed the button(s) on that caused you to do the attack.
 * Turn-jump threshold

External links and credits
ThomasTipman, for hitbox gifs. SuperDoodleMan, for his awesome collection of frame data as well as the terminology index. Percentages from Official Nintendo Power guide.