3-D Man

A-Bomb (HAS)

A.I.M.

Aaron Stack

Abomination (Emil Blonsky)

Abomination (Ultimate)

Absorbing Man

Abyss

Abyss (Age of Apocalypse)

Adam Destine

Adam Warlock

Aegis (Trey Rollins)

Aero (Aero)

Agatha Harkness

Agent Brand

Agents of Atlas

Agent X (Nijo)

Agent Zero

Aginar

Air-Walker (Gabriel Lan)

Ajak

Ajaxis

Akemi

Alain

Albert Cleary

Albion

Alexa Mendez

Alexander Pierce

Alex Power

Alex Wilder

Alice

Alicia Masters

Alpha Flight

Alpha Flight (Ultimate)

Alvin Maker

Amadeus Cho

Amanda Sefton

Amazoness

American Eagle (Jason Strongbow)

Amiko

Amora

Amphibian (Earth-712)

Amun

Ancient One

Ancient One (Ultimate)

Angel (Angel Salvadore)

Angel (Thomas Halloway)

Angel (Ultimate)

Angel (Warren Worthington III)

Angela (Aldrif Odinsdottir)

Anita Blake

Anne Marie Hoag

Annihilus

Anole

Ant-Man (Eric O'Grady)

Ant-Man (Hank Pym)

Ant-Man (Scott Lang)

Anthem

Apocalypse

Apocalypse (Ultimate)

Aqueduct

Arachne

Araña

Arcade

Arcana

Archangel

Arclight

Ares

Argent

Armadillo

Armor (Hisako Ichiki)

Armory

Arnim Zola

Arsenic

Artiee

Asgardian

Askew-Tronics

Asylum

Atlas (Team)

Attuma

Aurora

Avalanche

Avengers

Avengers (Ultimate)

Azazel (Mutant)

Balder

Banshee

Banshee (Theresa Rourke)

Baroness S'Bak

Baron Mordo (Karl Mordo)

Baron Strucker

Baron Zemo (Heinrich Zemo)

Baron Zemo (Helmut Zemo)

Barracuda

Bart Rozum

Bastion

Batroc the Leaper

Battering Ram

Battlestar

Beak