snake type game (dynamic array / list)

hi, I am trying to make a game like Snake but I'm having some problems with the main character. I have code that allows a set amount of pieces that have to be assigned in the inspector, however, what I want is for the player to start with 4 parts of a body and on collision for a new part to be generated and assigned a primitive.

the problem I am coming across is that I need the transform of the object to add to the list version but I don't know how to generate a new object then assign its transform to the list.

 public Transform[] chains; // static from inspector
     const float dist = 2;
     List<Transform> transList = new List<Transform>();
 
     void Update () {
         ChainLink ();
         //ChainLinkList ();
     }
 
     void ChainLink(){
         Vector3 prevLocation = transform.position;        //set the prevLocation to the currant Position 
 
         foreach (Transform chain in chains) {            
             Vector3 direction = (prevLocation - chain.position).normalized; //set direction to normalised version of position - the prevLocation
             chain.position = prevLocation - direction * dist;
             prevLocation = chain.position;
         }
     }
         
 //    void ChainLinkList(){
 //        Vector3 prevLocation = transform.position;        //set the prevLocation to the currant Position 
 //
 //        foreach (Transform chainList in transList) {
 //            Vector3 direction = (prevLocation - chainList.position).normalized; //set direction to normalised version of position - the prevLocation


 //            chainList.position = prevLocation - direction * dist;
 //            prevLocation = chainList.position;
 //        }
 //    }
 //
 //    void OnCollisionEnter(){
     //        transList.Add ( // need the transform of the object to add); // GameObject.CreatePrimitive (PrimitiveType.Sphere);
 //    }

any help would be appreciated.