Baboon of the Forest is a series of Level 7 Beast monsters with 2600 ATK and 1800 DEF. They each have an effect that activates when a Beast monster is destroyed and sent to the Graveyard. Their names are differentiated by their color and "occupation" in respect to the forest. All members of this series are EARTH monsters, except for the LIGHT "Ancient Crimson Ape". Naoki Shima from Yu-Gi-Oh! VRAINS uses a Deck based on this series.
Baboon Burn Decks, popular in 2007, revolve around the card "Green Baboon, Defender of the Forest" and cards that inflict effect damage.