The aim of UML Actions is to allow detailed and platform independent modeling of object-oriented behavior. However, behavior modeling with UML actions is still not adopted due to three main reasons. First, UML defines only the abstract syntax of the actions and no concrete syntax. Second, users have to work directly with the very complex meta-model of UML actions. Third, all existing tools do not provide appropriate support for creating and working with action-based behavior models. In this paper, we propose a hybrid language combining the strengths of textual and graphical notations in one concrete syntax for UML actions and present a supporting editor. We also report on a user study that was conducted to evaluate the notation and the editor.