In 2011, Moshi Monsters creator Mind Candy was sued by Lady Gaga over a Moshling (pet) featured in the game, a pop star baby named Lady Goo Goo, which they planned to release a song sung by on iTunes, titled "The Moshi Dance". The song was banned from being released on iTunes, but Lady Goo Goo was permitted to continue appearing in the game. However, Lady Goo Goo would still be replaced with a new pop star/infant-themed Moshling named Baby Rox.

In 2015, developers Mind Candy and 55pixels were ordered by the United Kingdom's Advertising Standards Authority (ASA) to change the wording of their in-app advertisements in Moshi Monsters and Bin Weevils, arguing that said wording was directly pressuring young players to pay for subscriptions (Moshi Monsters claimed that members would be "super popular", while Bin Weevils' options for subscriptions were phrased as commands). They also claimed that certain phrases used in the games, such as Moshi Monsters' "The Super Moshis need YOU" and Bin Weevils' interpretive phrases such as "DOSH Top Up", put pressure on children to pay. Both developers conceded to the ASA's demands, with Mind Candy claiming it took its "responsibilities very seriously with regards to how we communicate with all of our fans, especially children".

On March 22, 2022, former animator Chris Georgenes uploaded a trio of test animations he had made for Moshi Monsters showcasing the interactive emotions of the player's pet monsters like Diablo and Furi. Most notably, the third video featured animations for a scrapped pet monster called the "Jelli", whose design would later be used for various NPCs in the game, including Snozzle Wobbleson, the owner of the Gross-ery Store.