clay pigeon

clay pigeon  {n.},  {slang},  {informal}

1. A popular target at practice shooting made of clay and roughly resembling a pigeon; an easy target that doesn't move.

All he can shoot is a clay pigeon.

2. A person who, like a clay pigeon in target practice, is immobilized or is in a sensitive position and is therefore easily criticized or otherwise victimized.

Poor Joe is a clay pigeon.

3. A task easily accomplished like shooting an immobile clay pigeon.