Boss fights are a time-honored tradition in video gaming, with countless memorable boss battles over the years. However, some of the most memorable boss battles in games go overlooked because they are hidden away, sometimes forcing players to complete obscure tasks in order to trigger them.

These secret boss fights range from epic battles against especially powerful enemies to jokes put in for laughs by the game designers. Whether they were funny, especially challenging, or a mixture of both, the 10 secret boss battles listed here stand out as the best in gaming history.

10 The Cow King (Diablo 2)

When the original Diablo was popular, a rumor made the rounds that the game had a secret cow level for players to discover. This turned out to be a hoax, but the rumor was popular enough that it inspired Blizzard to add a secret cow level to the sequel, Diablo 2. The secret cow level is inhabited by the Hell Bovines, who are led by the Cow King - a male cow who has udders and is somehow able to produce milk. The Cow King would reappear in Diablo 3 as a ghost, alongside the Cow Queen and Cow Princess.

9 Driviks (Destiny: The Taken King)

Destiny: The Taken King is credited for revitalizing the original Destiny, and it also deserves a nod for having one of the best secret bosses in gaming history. By going off the beaten path in the Heroic version of the Lost to Light story mission, players can board a Fallen ketch filled with Taken, including the boss Driviks, the Chosen. Players are given a strict time limit of 10 minutes to kill Driviks and all of the other enemies aboard the ketch, and if they do so fast enough, they will unlock the Black Spindle exotic sniper rifle for their trouble.

8 Emerald Weapon (Final Fantasy 7)

Many Final Fantasy games have secret bosses players can choose to take on, but few are as memorable as the battle with Emerald Weapon in Final Fantasy 7. Emerald Weapon is located at the bottom of the ocean, reachable only by using the submarine. The battle against Emerald Weapon is one of the toughest fights in the game, with players only having 20 minutes to win. There are ways to make the boss fight easier, but any unprepared players that happen upon the Emerald Weapon while exploring the ocean will likely be facing a game over.

7 Father Rodin (Bayonetta)

Bayonetta is a game known for its extreme action and tough but fair challenge. However, one of the game's greatest challenges may go overlooked by many, as it comes in the form of a secret boss fight with Rodin, the Gates of Hell merchant who players purchase items from throughout the game.

To unlock the fight, players first have to obtain 10 million halos (Bayonetta's in-game currency), and then purchase a Platinum Ticket for 999,999 halos. Doing so will transform Rodin into Father Rodin, and what ensues is a boss battle similar to the one against the game's actual final boss, Father Balder, except with the difficulty turned up to 11.

Only truly dedicated Bayonetta players would have ever discovered this fight, and only the truly dedicated can hope to make it out alive. Needless to say, the upcoming Bayonetta 3 for the Switch will need to have a truly spectacular secret boss battle if it hopes to top this one.

6 Moon Presence (Bloodborne)

Like its Dark Souls sister series, Bloodborne is known for its highly challenging and outright brutal boss battles. One of the game's most intimidating bosses is the secret boss called Moon Presence, which can only be confronted if players eat three of the Umbilical Cords and then fight Gehrman, the First Hunter.

5 Morgan Freeman (South Park: The Fractured But Whole)

In South Park: The Fractured But Whole, celebrity Morgan Freeman has moved to the quiet little mountain town of South Park to open a Mexican restaurant called Freeman's Tacos. While Morgan Freeman is a wise, helpful character throughout most of the game, he also stands as its toughest boss battle. Players can initiate the extremely tough fight with Morgan Freeman at any time (unless they made a black character) by punching him a total of three times. What ensues is a frustratingly difficult fight against the most absurdly powerful boss in the entire game, so it may be best if players save this battle until the end.

4 Red (Pokemon Gold and Silver)

Pokemon Gold and Silver are notable for having two regions for players to explore in-game. After players have conquered the Johto region, they can return to the Kanto region from Pokemon Red, Blue, and Yellow where they can earn another eight gym badges. For all this effort, players are rewarded with the game's "true" final boss in the form of Red, the Pokemon trainer from the original games. Red has an extremely powerful roster of Pokemon at his disposal, making the fight against him one to remember.

3 Reptile (Mortal Kombat)

Fans may take Reptile for granted nowadays, but in the original Mortal Kombat, triggering the fight against him was a real challenge. Not only did players have to figure out how to unlock Reptile in a time when the Internet wasn't readily available to everyone, but they also had to play six games against the AI on the Pit stage, earn a Double Flawless Victory, and finish their opponent with a Fatality. Reptile would become a playable character in later Mortal Kombat games, while evolving into a much more lizard-like creature instead of a simple palette swap of Scorpion.

2 Sephiroth (Kingdom Hearts)

Sephiroth is one of the most notorious villains in video game history, and his infamy was solidified by his appearances in the Kingdom Hearts games. The fight against Sephiroth in the first Kingdom Hearts is remembered as arguably the toughest battle in the entire game, and served to make Sephiroth an even more imposing threat than ever before. Unfortunately for those who enjoyed the secret boss battle against Sephiroth, however, it's possible that he won't be in Kingdom Hearts 3.

1 Slot Machine (Star Fox)

There have been plenty of weird video game bosses over the years, and the Slot Machine in Star Fox is definitely one of the odder ones. Players can find this hidden encounter in the Out of This Dimension stage in the original Star Fox for the SNES. Defeating the Slot Machine is a matter of getting three red 7s, all the while trying to avoid the projectiles it constantly fires at Fox McCloud and the gang.

While these 10 secret bosses stood out to us the most, there have been plenty of other secret boss fights throughout the years that have also been well-received. One that comes to mind is the fight against Culex in Super Mario RPG: Legend of the Seven Stars, which feels like a boss battle pulled straight out of a Final Fantasy game.

Which secret boss fight is your favorite? Let us know your thoughts in the comments below.