This was my engineering viva question and I couldn't think of any example, for I am totally convinced that there cannot be drag in a inviscid flow. It also bothers me whether it is possible, a tricky scenario in fluid mechanics or gas dynamics.
Horseshoe vortex system in three dimension is a very good example for drag in a inviscid flow. See this
Unsteady inviscid flow can have drag. For example, an accelerating flat-plate at an angle of attack experiences a force parallel to it's motion. Same for an oscillating cylinder. See Principles of Ideal-Fluid Aerodynamics by Karamcheti for more details.