This paper presents a technique for replicating agents in a multi-agent system (MAS) with a goal of improving the fault-tolerance of the system. Replicating agents, or forming a replicate group, will always add complexity and overhead to a system. To mitigate these effects passive replication and a proxy agent is used to represent and manage the group. So that a new single point of failure (the proxy) is not created, the proxy is dynamic and can move to any agent in the replicate group. An implementation and experimentation is presented which shows that the technique is viable.