as in a really cool looking one? then you go to http://blender.org: http://www.blender.org/, download blender 2.49, look at a couple blender tutorials on youtube, make the character and save it as a .blend file in your unity project folder, and you should have a player prefab.

disclaimer: this should be a week long project. it doesnt take a couple hours or minutes to make a really cool looking character.

disclaimer2: you will have to check with the tornado twins tutorial on youtube to know what im doing in this script. the link for that is:

http://www.youtube.com/watch?v=5-X-Ebh1kYA&feature=related

if you're asking about a script, here's mine:

//shooting
 var bullitPrefab : Transform;
 //dying
 static var dead = false;
 static var SCORE = 0;

 //geting hit
 static var gotHit = false;

 //respawn
  function LateUpdate()
{



 if(dead)
 {//where the player respawns
  transform.position = Vector3(-30.76492, 1.086278, 1.999224);
  dead = false;
  }
  }


 function OnTriggerEnter( hit : Collider )
 {//when the player falls off (this doesnt really work too good. )
 if(hit.gameObject.tag == "fallout")
 {
  dead = true;
  //subtract life here
    HealthControl.LIVES -= 1;
 }

 //getting hit (this works)
  if(hit.gameObject.tag == "enemyProjectile")
  {
   gotHit = true;
   HealthControl.HITS += 1;
   Destroy(hit.gameObject);
  }
 }




/// This script moves the character controller forward 
/// and sideways based on the arrow keys.
/// It also jumps when pressing space.
/// Make sure to attach a character controller to the same game object.
/// It is recommended that you make only one call to Move or SimpleMove per frame. 

var speed : float = 6.0;
var jumpSpeed : float = 8.0;
var gravity : float = 20.0;

private var moveDirection : Vector3 = Vector3.zero;

function Update() 
{
var controller : CharacterController = GetComponent(CharacterController);
if (controller.isGrounded) {
// We are grounded, so recalculate
// move direction directly from axes
moveDirection = Vector3(Input.GetAxis("Horizontal"), 0,
Input.GetAxis("Vertical"));
moveDirection = transform.TransformDirection(moveDirection);
moveDirection *= speed;

//jumping
if (Input.GetButton ("Jump")) {
moveDirection.y = jumpSpeed;
}
}

// Apply gravity
moveDirection.y -= gravity * Time.deltaTime;

// Move the controller
controller.Move(moveDirection * Time.deltaTime);

//main menu button
if(Input.GetKeyUp("Escape"))
{
 Application.LoadLevel("Main Menu");
}

//shooting
if(Input.GetKey("f"))
   {//makes a fireball prefab
    var bullit = Instantiate(bullitPrefab, gameObject.Find("spawnPoint").transform.position, 
    Quaternion.identity);

    bullit.tag = "wormProjectile";
    //shoots it forward
    bullit.rigidbody.AddForce(transform.forward * 4000);
    //makes it go completely straight
    useGravity = false;

    }

    //prints your score
 print("Score: "+SCORE);
 //changes your score
 switch(SCORE)
 {
  case 10:
  Application.LoadLevel("Main Menu");
  break;
 }
}






    @script RequireComponent(CharacterController)

hope that helped.

you could always go to turbosquid and download one if you arent skilled enough to make one but there are a bunch of ways blender, mudbox, 3ds max whatever you will feel more comfortable with hope this helps good luck, Ben