From Dragon Ball Encyclopedia, the ''Dragon Ball'' wiki
The Saibaimen (サイバイマン, Saibaiman; FUNimation "Saibaman", Viz "Cultivar"; Literally meaning "Cultivationman") are a race of green, humanoid creatures who grow from seeds planted in soil.
Saibaimen possessed only enough intelligence to understand orders given to them by their leaders, thus they would never revolt. Developed in 737 Age by a scientist, they were a common tool of Freeza's Force due to their low cost, ease of mass production, and expendability. The Saibaimen used by Nappa and Vegeta were more advanced, thus their battle powers was around 1,200 and equal to that of Raditz. They were used at one time to train Kid Vegeta, who made easy work of them.. Prior to the destruction of Planet Vegeta, Saibaimen were frequently used by Freeza's Force in training exercises for young warriors. In one scene, Vegeta effortlessly defeated a large number of them at the age of four. It is assumed that they were used as expendable manpower in Freeza's Force.
Dragon Ball Z
Only six were left after the Tritekian conflict, and were planted by Nappa on Earth during a fight against the Z Warriors. One was destroyed by Vegeta because it failed to defeat Tenshinhan. Another used the Saibamen Bomb self-destruct attack in order to kill Yamucha and itself. Three were defeated by Kuririn's expanding energy wave, and the last was killed by Piccolo (after stopping it from attacking Son Gohan).
Dragon Ball GT
In Dragon Ball Z: Budokai 2's Story mode, Doctor Gero created a cadre of multi-color Saibaimen clones named Saibaimen Rangers (which were a parody of Super Sentai and/or Power Rangers). Once defeated (along with Gero), No. 16, No. 17, and No. 18 appeared. Normal Saibaimen appeared as common enemies.
Saibaimen were recurring enemies in Dragon Ball Z: Sagas. There were also large, blue, muscular-Saibaimen (Elite Saibaiman or Saibaibrute), who may have been inspired by the Bio-Men, Doctor Uiro's Saibaimen-like underlings.
In Raditz's what if story in Dragon Ball Z: Budokai Tenkaichi 2, Raditz was unable to defeat Piccolo (unlike the main DBZ story) and was forced to summon the aid of a Saibaiman, but his Saibaiman turned against him (seemingly it was defective) and self-destructed, causing Raditz to lose his memory of his Saiyan Heritage (just like Goku did), thus setting in motion the events of his what if story.
Many types of Saibaimen appeared in "Dragon Ball Z: Sūpā Saiya Densetsu". These included Kaiwareman (blue, with fighting power 238 - 338), Kyuukonman (red, with fighting power 326 - 426), Kopiiman (black, with fighting power 1000, which increases when they transform into one of the heroes), Saibaiman (green, with fighting power 1200), Ten'nenman (purple, with fighting power 2200 - 2400), and Jinkouman (gray, with fighting power 4400-4800).
They are also set to appear in Dragon Ball: Raging Blast 2.
Saibaimen are vicious plant/animal alien hybrids, they are used by both the Saiyans and Freeza's Force as grunts to root out weaker opponents or to assess an opponent's power (when a Scouter is not an option) and skill level (which Scouters cannot reveal). Saibaimen are also used by them in training (as seen in Vegeta's childhood; where he is show killing them effortlessly) as they are brutal fighters and can test a fighter abilities. They are said to be as strong as a typical low-class Saiyan (though this may only apply to Nappa's Saibaimen).
- Bukujutsu – Like almost all Dragon Ball Z characters, Saibaimen are able to fly through use of Ki.
- Full Power Energy Wave – Basically a fully powered energy wave shot from the palm. Is similar to the Kamehame-Ha and Galick Gun in basic fuction.
- High Speed Rush – A basic High Speed combo of Ki-enhanced claw slashes, punches, and kicks.
- Ki Blast – The most basic form of energy wave.
- Saibaiman Bomb (Jibaku) – The Saibaiman Bomb is a Saibaiman's ace in the hole, a kamikaze technique that turns the Saibaiman into a living bomb who grabs hold of its opponent and quickly self-destructs. The Saibaiman fighting Yamucha kills him in the first and the only successful Jibaku-type technique in the series. This attack was not named in the anime and is referred to as the Saibaiman Bomb only in Budokai Tenkaichi 3.
- Seed Planters – Saibaimen can be grown in most planets soil (Nappa said they would grow well in Earth's soil), the seeds are contained in a small bottle, with a greenish liquid in the bottom (possibly a fertilizer or quick growing solution). Placing the seed and pouring the liquid on them will start the growth proccess.
- Triple Acid – One of many of the Saibaimen's deadly, secrets is that they spray acid from a gland hidden in their head. This acid capable of eat though earth and likely flesh. This technique is a natural Saibiaman adaptation.
- Zanzo-ken – This technique is a short burst of extremely high speed, moving faster than the opponent can sense. This has the side effect of leaving a momentary "after image" until the opponent's senses adapt and realize their target has moved.
- A Saibaiman is the first character in the Dragon Ball Z series to use self-destruction as an attack when one of them kills Yamucha.
- A Saibaiman makes a cameo appearance in the manga series Rosario + Vampire.
- Goku never encounters the Saibaimen in either the manga or the anime. Goku does meet them (a lot of them) in Dragon Ball Z: Budokai 2's Story mode (and comical meetings at that, typical of good-natured Goku).
- Re-colorations of the Saibaimen, named the Saiba Rangers (a parody of the Power Rangers as all of them are colored differently) and created by Doctor Gero, appear in Budokai 2.
- Nappa seems to be very knowledgeable about Saibaimen and knows how to grow them (he seems to enjoy planting them). He even shows some slight compassion for them as he is shocked when Vegeta kills one of them after he fails to kill Tenshinhan. He is even shown coaching the Saibaimen who later kills Yamucha and is later angry that its fight ended in a draw. He states that settling for a draw was pathetic. After Kuririn and Piccolo kill many of the remaining Saibaimen, Nappa begs Vegeta to let him kill the five remaining Z Warriors (possibly to avenge the fallen Saibaimen, but it is more likely that he is upset that his toys are broken).
- They are named Cultivars in the VIZBIG edition of the manga.
- Akira created Imp monsters for Chrono Trigger who look like a cross between Namekians and Saibaimen.
- It is stated in a character biography for the Saibaimen in Dragon Ball Z: Budokai Tenkaichi that they were invented by scientists and made their way into Freeza's Force via the Saiyans. They were then used after they learned how to understand orders.