Darkmoon Ticket is a currency in the Darkmoon Faire. And you can get the Darkmoon Ticket by helping the merchant of the Darkmoon Faire to collect some of the quest items or to finish a special professional quest or daily quest. When Darkmoon Faire comes, you can redeem wow mount, wow pet, or some transmog items with Darkmoon Ticket.
The Darkmoon Faire always come on the first week of each month and usually last for one week. How many Darkmoon Tickets can you get in such a short time?

105 for completing both pet dailies seven days.
80 for dungeon and PvP books.
42 for completing six minigames for seven days.
20 for primary and secondary profession quests.
10 for turning in 250 ears for Test Your Strength.
10 for completing Den Mother's Demise, starts from Moonfang's Pelt from Moonfang.

14 for completing The Real Race and The Real Big Race for seven days

An additional amount can be obtained once per character:

100 for completing the quest Silas' Secret Stash

Also the black market item Darkmoon Ticket Fanny Pack could also get a lot of Darkmoon Tickets. You can use wow gold to bid Darkmoon Ticket Fanny Pack in the black market, and each Darkmoon Ticket Fanny Pack could open 200-500 Darkmoon Tickets randomly.
You can redeem the new mount Darkmoon Dirigible with 1000 Darkmoon Tickets. Collecting the Darkmoon Ticket slowly by daily quest or quickly with Darkmoon Ticket Fanny Pack, it will be your choice.