src/game/java/net/minecraft/client/model/GhastModel.java

package net.minecraft.client.model;

import net.minecraft.client.model.geom.ModelPart;
import net.minecraft.client.model.geom.PartPose;
import net.minecraft.client.model.geom.builders.CubeListBuilder;
import net.minecraft.client.model.geom.builders.LayerDefinition;
import net.minecraft.client.model.geom.builders.MeshDefinition;
import net.minecraft.client.model.geom.builders.MeshTransformer;
import net.minecraft.client.model.geom.builders.PartDefinition;
import net.minecraft.client.renderer.entity.state.GhastRenderState;
import net.minecraft.util.Mth;
import net.minecraft.util.RandomSource;
import net.minecraftforge.api.distmarker.Dist;
import net.minecraftforge.api.distmarker.OnlyIn;

@OnlyIn(Dist.CLIENT)
public class GhastModel extends EntityModel<GhastRenderState> {
    private final ModelPart[] tentacles = new ModelPart[9];

    public GhastModel(ModelPart p_170570_) {
        super(p_170570_);

        for (int i = 0; i < this.tentacles.length; i++) {
            this.tentacles[i] = p_170570_.getChild(createTentacleName(i));
        }
    }

    private static String createTentacleName(int p_170573_) {
        return "tentacle" + p_170573_;
    }

    public static LayerDefinition createBodyLayer() {
        MeshDefinition meshdefinition = new MeshDefinition();
        PartDefinition partdefinition = meshdefinition.getRoot();
        partdefinition.addOrReplaceChild(
            "body", CubeListBuilder.create().texOffs(0, 0).addBox(-8.0F, -8.0F, -8.0F, 16.0F, 16.0F, 16.0F), PartPose.offset(0.0F, 17.6F, 0.0F)
        );
        RandomSource randomsource = RandomSource.create(1660L);

        for (int i = 0; i < 9; i++) {
            float f = (((float)(i % 3) - (float)(i / 3 % 2) * 0.5F + 0.25F) / 2.0F * 2.0F - 1.0F) * 5.0F;
            float f1 = ((float)(i / 3) / 2.0F * 2.0F - 1.0F) * 5.0F;
            int j = randomsource.nextInt(7) + 8;
            partdefinition.addOrReplaceChild(
                createTentacleName(i), CubeListBuilder.create().texOffs(0, 0).addBox(-1.0F, 0.0F, -1.0F, 2.0F, (float)j, 2.0F), PartPose.offset(f, 24.6F, f1)
            );
        }

        return LayerDefinition.create(meshdefinition, 64, 32).apply(MeshTransformer.scaling(4.5F));
    }

    public void setupAnim(GhastRenderState p_365609_) {
        super.setupAnim(p_365609_);

        for (int i = 0; i < this.tentacles.length; i++) {
            this.tentacles[i].xRot = 0.2F * Mth.sin(p_365609_.ageInTicks * 0.3F + (float)i) + 0.4F;
        }
    }
}