Mulch is commonly used in landscaping. Most types of mulch are safe, however, cocoa bean mulch is not safe.
The cocoa bean produces beautiful dark mulch that has the aroma of chocolate. Unfortunately, this type of mulch is dangerous because of the by-products of the cocoa shells. When ingested, dogs can show severe signs of chocolate toxicity. If you have dogs, especially one that likes to "eat things", consider other type of safer mulch in your landscaping plans.
For more information about cocoa bean mulch toxicity, please read Cocoa Mulch Toxicity