Here are a few possibilities:
* A friendly dog: This is the most straightforward opposite. A friendly dog is approachable, playful, and doesn't pose a threat to people or other animals.
* A well-trained dog: A well-trained dog understands commands and is less likely to act in ways that could be considered dangerous.
* A gentle dog: A gentle dog is calm and doesn't exhibit aggressive behaviors.
* A safe dog: This is a broader term that encompasses any dog that doesn't present a risk to people or other animals.
It's important to remember that any dog can be dangerous if it's not properly socialized and trained. The best way to ensure your dog is safe and friendly is to provide proper training and socialization.