Or, "to twiddle your/one's thumbs". However, I'm not sure I agree with "to be a lazybones". I think being lazy is stronger than just being idle.
When someone is desperate to fill some kind of job position, but cannot find an acceptable candidate, he or she might settle for someone with poor skills, saying, "we just need a warm body" or "a warm body is better than no body." This "warm body" does the bare minimum of work, and not well; mainly they are just a physical presence instead of a productive worker.