Turf Wars are a mechanic introduced into Monster Hunter World. When two monsters meet, they might engage in a cinematic battle where either one or both monsters take significant damage and drop an item.
List of Monster Turf Wars
Monster Hunter World: Iceborne
For more information, see MHWI: Turf War List
Monster Hunter Rise
For more information, see MHRise: Turf War List
Bond Attacks are a mechanic introduced into Monster Hunter World with the introduction of Lunastra as a DLC. They are a special attack that has two monsters fuse their attacks together to create a massive, highly damaging attack. So far the only monsters that can do this are Teostra and Lunastra.
List of Monster Bond Attacks
Ambush is a special turf war from Crimson Glow Valstrax in Monster Hunter Rise. It consists of Valstrax plummeting from the sky, hitting and knock-out the monster that is on the stage. This attack is also used to attack the hunter.