A ripper tooth for use mounted on an excavation tool having a tool body mounted for rotation on an excavation machine arm, the ripper tooth being mounted to the tool body for ripping engagement with a substrate. The ripper tooth has first and at least second portions, each with a tip disposed for ripping engagement with the substrate. The first and second portions are laterally spaced apart generally along the axis of rotation of the tool relative to the arm, and the first and second portions are angularly spaced apart generally in a direction of substrate ripping motion. The first portion is disposed on a first axis and the second portion is disposed on a second axis, the first and second axes being different. Ripper excavation tools with one or more ripper teeth of the disclosure mounted to the tool body are also described.