Why is my armor rendering like this?

[hypov]

Entity Code:

package io.github.withonetee.entities;

import io.github.withonetee.init.ModEntity;
import net.minecraft.block.BlockState;
import net.minecraft.enchantment.Enchantments;
import net.minecraft.entity.*;
import net.minecraft.entity.ai.attributes.AttributeModifierMap;
import net.minecraft.entity.ai.attributes.Attributes;
import net.minecraft.entity.ai.goal.*;
import net.minecraft.inventory.EquipmentSlotType;
import net.minecraft.item.IDyeableArmorItem;
import net.minecraft.item.ItemStack;
import net.minecraft.item.Items;
import net.minecraft.util.DamageSource;
import net.minecraft.util.SoundEvent;
import net.minecraft.util.SoundEvents;
import net.minecraft.util.math.BlockPos;
import net.minecraft.util.text.ITextComponent;
import net.minecraft.world.BossInfo;
import net.minecraft.world.World;
import net.minecraft.world.server.ServerBossInfo;

public class FightingEntity extends MonsterEntity {

    private final ServerBossInfo bossInfo = (ServerBossInfo) (new ServerBossInfo(this.getDisplayName(), BossInfo.Color.RED, BossInfo.Overlay.PROGRESS)).setDarkenSky(true);
    public final ItemStack leather_helmet = new ItemStack(Items.LEATHER_HELMET);
    public final ItemStack cookie = new ItemStack(Items.COOKIE);

    public FightingEntity (EntityType<? extends MonsterEntity> type, World worldIn) {
        super(type, worldIn);
    }

    @Override
    public void onAddedToWorld() {
        super.onAddedToWorld();
        this.setSprinting(true);
        ((IDyeableArmorItem) leather_helmet.getItem()).setColor(leather_helmet, 0xBFA290);
        cookie.addEnchantment(Enchantments.KNOCKBACK, 2);
        this.setItemStackToSlot(EquipmentSlotType.MAINHAND, cookie);
        this.setItemStackToSlot(EquipmentSlotType.HEAD, leather_helmet);
    }

    public static AttributeModifierMap.MutableAttribute setCustomAttributes() {
        return MobEntity.func_233666_p_()
                .createMutableAttribute(Attributes.MAX_HEALTH, 300.0F)
                .createMutableAttribute(Attributes.MOVEMENT_SPEED, 0.4F)
                .createMutableAttribute(Attributes.ATTACK_KNOCKBACK, 3.0F)
                .createMutableAttribute(Attributes.ATTACK_SPEED, 100.0F)
                .createMutableAttribute(Attributes.ATTACK_DAMAGE, 5.0F)
                .createMutableAttribute(Attributes.ARMOR, 0.0F)
                .createMutableAttribute(Attributes.ARMOR_TOUGHNESS, 0.0F);
    }

    @Override
    public void registerGoals() {
        super.registerGoals();
    }

    @Override
    public int getExperiencePoints(PlayerEntity player) {
        return 25 +  this.world.rand.nextInt(50);
    }

    @Override
    public SoundEvent getAmbientSound() {
        return SoundEvents.ENTITY_CAT_AMBIENT;
    }

    @Override
    public SoundEvent getDeathSound() {
        return SoundEvents.ENTITY_CAT_DEATH;
    }

    public SoundEvent getHurtSound(DamageSource damageSourceIn) {
        return SoundEvents.ENTITY_CAT_HURT;
    }

    @Override
    public void playStepSound(BlockPos pos, BlockState blockIn) {
        this.playSound(SoundEvents.ENTITY_PIG_STEP, 1.0F, 1.0F);
    }

    @Override
    public boolean canSwim() {
        return true;
    }

    @Override
    public SoundEvent getSwimSound() {
        return SoundEvents.ENTITY_PLAYER_SWIM;
    }

    @Override
    public SoundEvent getSplashSound() {
        return SoundEvents.ENTITY_PLAYER_SPLASH;
    }

    @Override
    public SoundEvent getFallSound(int heightIn) {
        return SoundEvents.ENTITY_PLAYER_BIG_FALL;
    }

    @Override
    public boolean canBreatheUnderwater() {
        return true;
    }

    @Override
    public boolean preventDespawn() {
        return true;
    }

    @Override
    public boolean canDespawn(double distanceToClosestPlayer) {
        return false;
    }

    @Override
    public boolean isDespawnPeaceful() {
        return false;
    }

    @Override
    public boolean onLivingFall(float distance, float damageMultiplier) {
        return super.onLivingFall(distance, 0);
    }

    @Override
    public boolean isNonBoss() {
        return false;
    }

    @Override
    public void updateAITasks() {
        super.updateAITasks();
        bossInfo.setPercent(getHealth() / getMaxHealth());
    }

    @Override
    public void addTrackingPlayer(ServerPlayerEntity player) {
        super.addTrackingPlayer(player);
        bossInfo.addPlayer(player);
    }

    @Override
    public void removeTrackingPlayer(ServerPlayerEntity player) {
        super.removeTrackingPlayer(player);
        bossInfo.removePlayer(player);
    }
}

Renderer:

package io.github.withonetee.client.render;

import io.github.withonetee.Main;
import io.github.withonetee.client.model.EntityPlayerModel;
import io.github.withonetee.entities.FightingEntity;
import net.minecraft.client.renderer.entity.EntityRendererManager;
import net.minecraft.client.renderer.entity.LivingRenderer;
import net.minecraft.client.renderer.entity.layers.BipedArmorLayer;
import net.minecraft.client.renderer.entity.layers.HeldItemLayer;
import net.minecraft.util.ResourceLocation;

public class EntityFightingRenderer extends LivingRenderer<FightingEntity, EntityPlayerModel<FightingEntity>> {

    public EntityFightingRenderer(EntityRendererManager manager) {
        super(manager, new EntityPlayerModel(0.0F, false), 0.5F);
        this.addLayer(new BipedArmorLayer<>(this, new EntityPlayerModel<>(0.5F, false), new EntityPlayerModel<>(1.0F, false)));
        this.addLayer(new HeldItemLayer<>(this));
    }

    @Override
    public ResourceLocation getEntityTexture(FightingEntity entity) {
        return new ResourceLocation(Main.MOD_ID, "textures/entity/entity.png");
    }
}