Inspired by Cesar Baldaccini, whom he met at the age of 7, Lagasse turned to sculpture while maintaining his love for graffiti, a form of artistic expression that he practiced in the streets and subways. A pivotal encounter with Yvaral Vasarely opened up new perspectives and encouraged him to merge graffiti with sculpture.
In 2009, he created his signature piece entitled "One dollar". This piece is the result of his admiration for the United States and his idea of "making art with $1". Lagasse has declined this work in many colors and with various materials.
In 2016, he pushed the limits of his creation by creating a monumental bronze sculpture, a "One dollar" measuring 2 meters high and weighing 500 kg. This one was exhibited at the Paris Art Fair.
In 2017, Karl Lagasse designed the trophy for the 43rd edition of the Deauville American Film Festival, inspired by the sea and the waves.