This character is from Henry V.
Pistol is one of the old Boar's-Head Tavern group, who have now become cheaters and thieves in the English army in France.
Here is Pistol's character analysis at eNotes. You can find out more about him and other characters by following the link below.
"Ancient (Ensign) Pistol is Hostess Quickly's husband as well as a crony and fellow soldier to Bardolph and Nym, with whom he goes to the French wars. He is what the Elizabethans refer to as a swaggerer—a bully who swears and brags but who runs away at the first sign of danger. The boy acting as Pistol's servant calls him a coward with "a killing tongue and a quiet sword" (III.ii.34). Gower describes him as "a gull, a fool, a rogue, that now and then goes to the wars, to grace himself at his return into London under the form of a soldier" (III.vi.67-69). Near the close of the play in V.i, Pistol is beaten by Fluellen for his insolent attacks on the captain's Welsh heritage and forced to eat a leek which is the symbol of Wales.
Pistol and his cronies expose the hypocrisy behind Henry V's war with France, appearing as they do immediately after the Chorus and therefore apparently undercutting the Chorus's patriotic descriptions of Henry's troops as enthusiastic, honor-seeking "English Mercuries" (Ch.II.7). In contrast, others assert that dishonest characters like Ensign Pistol come to ruin in the play and are replaced by honest characters like Captain Fluellen who prosper under Henry."