Demand Overload: Physical copies of Ultra Kaiju Monster Rancher sold out in many storefronts shortly after release, to the point that the official Twitter account issued an apology.
Dueling Games: Monster Rancher was formally accepted as one of Sony's counters to Nintendo's Pokémon, even going so far as to include PlayStation references in the animated series. However, it stopped being a PlayStation-exclusive series with the release of Monster Rancher Advance for Game Boy Advance.
Lepus, a Pixie/Hare, has Hare's 1-2 Punch in Japan as a default move but the English releases beefed the hex conversion and the tech was lost.
International releases of MR2 censored Kato's Oil Fire and Oil Flame techniques. Still doesn't change the fact that NPC Katos can have them, though.
Fandom VIP: The late Lisa Shock, owner of the popular fansite Monster Rancher Metropolis and known for her research into the game mechanics, who is credited under "special thanks" in the third, fourth, and fifth game and in the Updated Re-release of the first two games.
Follow the Leader: The mobile game Monster Farm Line plays almost identically to Uma Musume Pretty Derby, the only real difference being that instead of automated races you have the classic monster rancher battle system.
The original Monster Rancher never came out in PAL regions.
The first Nintendo DS game was never released outside Japan.
Monster Farm Online, the MMORPG. Even if you go through the trouble of signing up for a Japanese account, you can't play it because it blocks all foreign IPs.
Monster Farm POP 1, 2, and Monster Farm Travel were never released outside Japan.
The original Monster Rancher never came out in PAL regions—instead, its sequel, Monster Rancher 2, came out first with the number dropped. This caused certain aspects of the anime and the spinoff games to become cases of Marth Debuted in "Smash Bros."—the Dino species were MR1 only.
Similarly, the original DS game never came out in English. English-speaking markets got DS 2 instead, with the similarly-dropped number.
Technology Marches On: One of the most well-known features of the early games is their ability to accept CDs, DVDs, and game disks to create monsters. Then the first game got an Updated Re-release to platforms that don't use disks whatsoever. The solution? An online "CD Database" that allows you to look up CDs (including modern releases!) and Nintendo Switch games via a search engine and produce monsters with the results.
Urban Legend of Zelda: Monster Rancher Metropolis, a well-known site for MR data and gameplay tips, got several things wrong that snowballed into rumors only debunked in 2018.
The Fairy Hare was said to have a boosted Speed stat due to a glitch in early versions of the game, but it actually had a boosted Guts regeneration.
The requirements to get a Beaclon, while strict, aren't as bad as many thought, and there is no random element if you do everything right.
Mocchis do not have a hidden luck stat.
The Anime
Acting for Two: Besides Genki Sakura, Saffron Henderson also voices Pixie. The said characters had a conversation in episode 10.
Breakaway Pop Hit: The third Japanese OP, "Close to Your Heart," became a hit single.
Executive Meddling: The series has an egregious example of this, deliberately editing any and all references to Monster Farm and TECMO due to the fact, supposedly, since they could not advertise within the series. This is despite the fact the series was one huge advert for the original game.
Missing Episode: The episodes "Tiger's Battle with Destiny" and "The Battle with the Big Bad Four" only aired once, and were taken out of syndicated airings until the series was released on DVD.
Network to the Rescue: The syndicated BKN broadcasted the anime early weekday mornings, and only reran (repeatedly) the first season. Fox Kids not only ran the first season on its Saturday morning line-up, but also broadcasted the second season. Unfortunately, they only ran the second season in full once.
Then, out of nowhere in 2002, it was quietly picked up by Kids WB, but only for its weekday block. Regardless, it only aired episodes of the first two seasons.
Genki Sakura's voice actor changed from Saffron Henderson to Andrew Francis. The reason for this is the former's wedding, which took place sometime in January or February 2001, conflicted with her voice acting commitments.
Golem's voice actor changed midway through season 2 from Richard Newman to Doc Harris.
Monol was voiced by David Kaye in the first season before being replaced by Brian Drummond in the next two seasons.
On the Japanese side of things, Tsutomu Kashiwakura replaced Kaneto Shiozawa as Gali during season 3 after the latter passed away between appearances.
Post-Script Season: The third season was produced after it was Un-Canceled. And after the shock of the second season's ending, the third season was... a jarring shift, to say the least.
Screwed by the Network: The first season was rerun into the ground, and the second season was only aired in full once, with two episodes swiftly being removed from rotation afterward: "Tiger's Battle with Destiny" and "Battle with the Big Bad Four": the final confrontations with Gray Wolf and Naga. The third season was dubbed but never aired in the US.
