Many BSM models contain particles that are charged under both Standard Model and Hidden Valley gauge groups, yet very little effort has been put into establishing their experimental signatures. I will provide a general overview of the collider phenomenology of spin 0 or 1/2 mediators with non-trivial gauge numbers under both the Standard Model and a single new confining group, with a focus on direct production with semivisible jets. For the mediators to be able to decay, a global U(1) symmetry must be broken. This is best done by introducing a set of operators explicitly violating this symmetry. I will show that there is only a finite number of such renormalizable operators and that the phenomenology can be classified into five distinct categories. I will also show that large regions of the parameter space are already excluded, while others are unconstrained by current search strategies. Finally I will discuss how searches could be modified to better probe these unconstrained regions by exploiting special properties of semivisible jets.