I'm trying to get my custom mob use an item in your hand ...

 

[spoiler=What I Tried]

public ItemStack getHeldItem()
     {
	 return heldItem;
     }

     private static final ItemStack heldItem = new ItemStack(ItemHandler.WandOfFire);

 

 

[spoiler=Model]

package rennancge.zanmagic.model;

import net.minecraft.client.model.ModelBase;
import net.minecraft.client.model.ModelRenderer;
import net.minecraft.entity.Entity;
import net.minecraft.util.MathHelper;

public class ModelWizard extends ModelBase
{
  //fields
    ModelRenderer head;
    ModelRenderer body;
    ModelRenderer rightarm;
    ModelRenderer leftarm;
    ModelRenderer rightleg;
    ModelRenderer leftleg;
    int heldItemLeft;
    int heldItemRight;
  
  public ModelWizard()
  {
    textureWidth = 64;
    textureHeight = 32;
    
    heldItemLeft = 0;
        heldItemRight = 0;
    
      head = new ModelRenderer(this, 0, 0);
      head.addBox(-4F, -8F, -4F, 8, 8, ;
      head.setRotationPoint(0F, 0F, 0F);
      head.setTextureSize(64, 32);
      head.mirror = true;
      setRotation(head, 0F, 0F, 0F);
      body = new ModelRenderer(this, 16, 16);
      body.addBox(-4F, 0F, -2F, 8, 12, 4);
      body.setRotationPoint(0F, 0F, 0F);
      body.setTextureSize(64, 32);
      body.mirror = true;
      setRotation(body, 0F, 0F, 0F);
      rightarm = new ModelRenderer(this, 40, 16);
      rightarm.addBox(-3F, -2F, -2F, 3, 12, 4);
      rightarm.setRotationPoint(-4F, 2F, 0F);
      rightarm.setTextureSize(64, 32);
      rightarm.mirror = true;
      setRotation(rightarm, 0F, 0F, 0F);
      leftarm = new ModelRenderer(this, 40, 16);
      leftarm.addBox(-1F, -2F, -2F, 3, 12, 4);
      leftarm.setRotationPoint(5F, 2F, 0F);
      leftarm.setTextureSize(64, 32);
      leftarm.mirror = true;
      setRotation(leftarm, 0F, 0F, 0F);
      rightleg = new ModelRenderer(this, 0, 16);
      rightleg.addBox(-2F, 0F, -2F, 4, 12, 4);
      rightleg.setRotationPoint(-2F, 12F, 0F);
      rightleg.setTextureSize(64, 32);
      rightleg.mirror = true;
      setRotation(rightleg, 0F, 0F, 0F);
      leftleg = new ModelRenderer(this, 0, 16);
      leftleg.addBox(-2F, 0F, -2F, 4, 12, 4);
      leftleg.setRotationPoint(2F, 12F, 0F);
      leftleg.setTextureSize(64, 32);
      leftleg.mirror = true;
      setRotation(leftleg, 0F, 0F, 0F);
  }
  
  public void render(Entity entity, float f, float f1, float f2, float f3, float f4, float f5)
  {
    super.render(entity, f, f1, f2, f3, f4, f5);
    setRotationAngles(f, f1, f2, f3, f4, f5, entity);
    head.render(f5);
    body.render(f5);
    rightarm.render(f5);
    leftarm.render(f5);
    rightleg.render(f5);
    leftleg.render(f5);
  }
  
  private void setRotation(ModelRenderer model, float x, float y, float z)
  {
    model.rotateAngleX = x;
    model.rotateAngleY = y;
    model.rotateAngleZ = z;
  }
  
  public void setRotationAngles(float f, float f1, float f2, float f3, float f4, float f5, Entity entity)
  {
    super.setRotationAngles(f, f1, f2, f3, f4, f5, entity);
    
    this.rightarm.rotateAngleX = (MathHelper.cos(f * 0.6662F) * 1.4F * f1);
    this.leftarm.rotateAngleX = (MathHelper.cos(f * 0.6662F + 3.1415927F) * 1.4F * f1);
    this.rightleg.rotateAngleX = (MathHelper.cos(f * 0.6662F) * 1.4F * f1);
    this.leftleg.rotateAngleX = (MathHelper.cos(f * 0.6662F + 3.1415927F) * 1.4F * f1);
    
    if (heldItemLeft != 0)
    {
        leftarm.rotateAngleX = leftarm.rotateAngleX * 0.5F - 0.3141593F * (float)heldItemLeft;
    }
    if (heldItemRight != 0)
    {
        rightarm.rotateAngleX = rightarm.rotateAngleX * 0.5F - 0.3141593F * (float)heldItemRight;
    }
  }

}

 

Please, be more specific.

I want my mob be holding a certain item when spawned

What is your current result?  A screenshot could be helpful if you suspect that it is holding the item but it isn't rendering right.

With what i tried:

 

You have no render code for held items.  Look at RenderZombie for an example, perhaps?

nope you did it wrong, you need to set your mob render to biped, and model if you have to biped

 

here  is my tutorial, for custom entity with working item holding and own biped model

 

 

http://rolikstuff.forumbuild.com/viewtopic.php?f=10&t=39:

 

 

and you only need to add this this.setCurrentItemOrArmor(0, new ItemStack(Items.golden_sword));

but not held item, it will work if you have biped or zombie render

Thanks, is working.