Axe Knight

Ax Knight is the most common of the Meta-Knights. He wears a skull mask, a viking-style helmet, and wields an ax nearly as big as himself. In-game appearances shows him to be wearing a skull mask, but in all appearances outside of the game of Revenge of Meta Knight shows him to be an actual skull. He serves under Meta Knight, but also played a role as a crew member of the Halberd with in-game dialogue.

Kirby's Adventure and Kirby: Nightmare in Dream Land
Ax Knight is one of the four Meta-Knights that together appear as a recurring mini-boss. Once Kirby enters the room they inhabit, Meta Knight gives the command before disappearing, and the Meta-Knights appear. Ax Knight stands in place, sometimes walking back and forth, as it swings its axe. It will occasionally throw its weapon like a Cutter, sometimes jumping over it as it comes back, similarly to Sir Kibble. In a rare few appearances, Ax Knight will slice its way across the room when spawned, turning and proceeding in the opposite direction once it reaches the end. Ax Knight gives no ability. Inhaling defeats it and it takes 2-3 hits with a Copy Ability like Freeze to defeat it.

Kirby Super Star and Kirby Super Star Ultra
In Super Star and its remake, Ax Knight behaves in the exact same way, except with a new attack. If the player gets too close to an Ax Knight, it will chase the player brandishing its axe back and forth. The only exception is that it appears on its own, not having to follow Meta Knight's command to attack.

Ax Knight also doubles as a key character in Meta Knight's Revenge. He serves as one of the crew members who overlook Kirby's journey through the Halberd. He is aware of Kirby's destruction, and does not respond well to sending Heavy Lobster to tear through part of the ship to smite Kirby. Before Kirby's encounter with Meta Knight, Ax Knight appears along with other Meta-Knights in an attempt to stop him. Obviously, this effort is in vain. In addition to his witty conversations with other crew members (sometimes, his comments and expressions prove to be in the least bit humorous), he also operates the Halberd, as seen in the opening cutscene.

In Meta Knightmare Ultra, the final boss Galacta Knight can summon galactic versions of Ax Knight, Javelin Knight, Mace Knight, and Trident Knight. The galactic version of Ax Knight is just a blue toned recolor, but it is capable of doing more damage and attacking faster.

In the ending credits of Meta Knightmare Ultra, he makes a brief cameo with Captain Vul, Sailor Dee, and Meta Knight in the interior of the Halberd.

Kirby's Pinball Land
Ax Knight appears at the top stage of Poppy Brothers' Land, but only once the player has beaten King Dedede at least once. If the player breaks all the Crack-Tweets out of their eggs, the sound of the microphone power-up from Kirby's Dream Land will sound, and Ax Knight will appear where the middle egg once was. He does not move and cannot be hit.

Trivia

 * In the comics, he is originally seen with Mace Knight most of the time they appear. It is a hint that they are close friends.
 * He has a fear of heights, as quoted while Kirby is making his way through the bottom of the ship, "And it's high." (Kirby Super Star Ultra) "I'm afraid of heights!" (Kirby Super Star).
 * His role as a crewman is operating/steering the Halberd, as it was shown in the opening credits. Most of the time, he reports statistics about the ship, along with Mace Knight.
 * There are many theories about what he actually is. In-game appearances shows him to have a skull mask and a black, round-ish body. But in the cutscenes, he is shown as a full skull as shown in the opening credits of Revenge of Meta Knight and the ending snapshot with the Halberd Crew at Milky Way Wishes (without the mask).

Quotes
"Ahh! Main Cannon #2 was destroyed!"

- Ax Knight

"Are we really going to do this?"

- Ax Knight, knowing something is up with his commander...

"Dyna Blade has been shot down!"

- Ax Knight,

"We got him on radar! He's in the ducts!"

- Ax Knight,

"Ahh...Looks like our battleship is falling apart..."

- Ax Knight in his dismay