|This article is about a/an episode in Mighty Morphin Power Rangers.|
Happy Birthday, Zack is the tenth episode of Mighty Morphin Power Rangers.
While the Rangers work on a surprise party for Zack, he thinks the others have forgotten about his birthday. Rita Repulsa proves she hasn't though. She sends him a present in the form of the Knasty Knight who is sent to destroy the Black Ranger, and make sure he never has another birthday!
The Rangers minus Zack are decorating the Youth Center one evening after hours for Zack's birthday the next day. Rita Repulsa wants to give Zack a gift of her own so Finster makes plans to create a monster.
To throw Ernie off their trail when discussing the Power Rangers, Jason and Billy tell him that the Rangers are aliens, not people. Bulk and Skull arrive to make some trouble but get their immediate comeuppance.
Finster and Rita decide on using the Knasty Knight for their plan. Baboo and Squatt help Finster weld the Knasty Knight's sword that same night. Once completed, Rita casts a spell to raise the Knight.
Later, Ernie spots Zack coming in to the center so the others hide until he leaves.
The next day, Zack runs into Kimberly at school and tries to hint about his birthday. Kimberly plays it off and says that it's her dog's birthday. Bummed out, Zack walks away. Kimberly tells her friends that Zack thinks that they all forgot his birthday. They have to keep his surprise party a secret, though.
Zack is ambushed by Rita and the Knight when he goes for a walk. He morphs but his Power Axe isn't working very well against the Knasty Knight's sword. Zordon alerts the other Rangers and they go to rescue Zack. None of them do any better against Knight and their weapons begin to corrode. The combined Blade Blasters don't help either. Rita makes Knasty Knight a giant and Megazord is summoned. Black Ranger realizes that Knight is winning because he's reflecting their energy. The solution: reflect Knight's energy along with sending forward some of their own. Megazord's eyes shoot some energy that freezes Knight's sword in place. Knasty Knight's blade is cut in half and Megazord finishes the monster off. Rita retreats back to the moon where she angrily blames her lackeys for the failure.
Back at the Youth Center, the gang brings Zack to his surprise party and they happily celebrate.
- Austin St. John as Jason Lee Scott (Mighty Morphin Red Ranger)
- Thuy Trang as Trini Kwan (Mighty Morphin Yellow Ranger)
- Walter Jones as Zack Taylor (Mighty Morphin Black Ranger)
- Amy Jo Johnson as Kimberly Ann Hart (Mighty Morphin Pink Ranger)
- David Yost as Billy Cranston (Mighty Morphin Blue Ranger)
- Paul Schrier as Farkas "Bulk" Bulkmeier
- Jason Narvy as Eugene "Skull" Skullovitch
- Richard Genelle as Ernie
- David Fielding as Zordon
- Romy J. Sharf as Alpha 5
- Richard Steven Horvitz as Alpha 5 (voice) (as Richard Wood)
- Machiko Soga as Rita Repulsa
- Barbara Goodson as Rita Repulsa (voice)
- Takashi Sakamoto as Goldar
- Kerrigan Mahan as Goldar (voice) (as Ryan O'Flannigan)
- Takako Iiboshi as Finster
- Robert Axelrod as Finster (voice)
- Minoru Watanabe as Squatt
- Michael J. Sorich as Squatt (voice)
- Hideaki Kusaka as Baboo
- Dave Mallow as Baboo (voice (as Colin Phillips)
- Tom Wyner as Knasty Knight (voice)
- Aohisa Takayasu as Zordon's Soldier
- In the flashback footage about the Knasty Knight, it is fighting the Black Ranger (MammothRanger) from the original Super Sentai show Kyoryu Sentai Zyuranger, Goushi.
- The fight itself was unusable since Goushi was unmorphed but they explained it as him being "Zordon's Soldier."
- This episode would be mentioned again by Zack in "Island of Illusion".
- First episode to have a Ranger celebrating a birthday.
- First episode where a Megazord has a proper fight with the monster instead of just overpowering them easily. This would become a staple in all seasons after tis, beginning with season 3 's "A Friend in Need: Part III".
- The original Zyuranger episode had a plot point where the sword was forged by a young boy and the weakness of the sword was the fact that it could not harm the child who forged it. The major edit was to remove the footage where the boy enters the Megazord's control room to help stop this Dora Monster.
- The eye beam the Megazord fires to stop the sword was added in the US to explain why he was unable to force it to strike (the Megazord couldn't be hit or it would have hurt Shigeru).
- The flashback footage of Zack fighting the Knasty Knight was used in "Crystal of Nightmares" which in turn was used for the Sega CD release of Mighty Morphin Power Rangers.
- In the second sequence in Rita's Palace, at the start, Goldar can be seen sleeping against the wall as Rita calls Finster for a monster idea.
- The episode contains a reference to the DC Comics hero Batman by Ernie (likening how the Rangers protect Angel Grove to Batman protecting Gotham City). Coincidentally, Mighty Morphin Power Rangers was at the time airing on the same weekday afternoon line-up as Batman: The Animated Series, another one of Fox Kids' hit shows. A later reference to Batman is made in the Dino Thunder episode "Day of the Dino".
- Jason suggests that the Power Rangers are space aliens from a distant planet when Ernie mentions a rumor that they are regular humans. True Alien Rangers would appear to replace the incapacitated Earth Rangers in the third season.
- According to the MMPR Interactive CD-ROM, assuming the series takes place in 1993, the events of this episode took place on May 3, 1993, the date given as Zack's birthday.
- Zack is the first Ranger to have a solo morph.
- The following monsters are seen in Finster's monster cookbook; Snizzard, Bones, Chunky Chicken, King Sphinx, Genie, Mr. Ticklesneezer, Mighty Minotaur, and Knasty Knight. All of these pictures are the monster's original concept art depictions from Japan.
- When Kimberly opens her locker, a hand can be seen holding the bottom of it.
- When Knasty Knight is blasting at the Black Ranger, on top of the hill to the right there appears to be two people tied up to polls even though Rita wasn't holding anybody hostage.
- After Zack morphs, the Power Axe is smoking and corroded before having made contact with Knasty Knight's sword. This because in the Zyuranger source during Goushi's fight with Dora Knight, the unmorphed version of the Moth Breaker clashed with the monster's sword Durandal.
- It was the same battle that they used for "Zordon's Warrior."
- The following monsters are seen in Finster's monster cookbook; Snizzard, Bones, Chunky Chicken, King Sphinx, Genie, Mr. Ticklesneezer, Mighty Minotaur, and Knasty Knight. However, Mr. Ticklesneezer and Genie were not technically created by Finster. Ticklesneezer was a doll before being zapped by a laser (and also part of a dream) and the Genie was just that.