diff --git a/examples/moving_fish.scad b/examples/moving_fish.scad
new file mode 100644
index 00000000..5c65a953
--- /dev/null
+++ b/examples/moving_fish.scad
@@ -0,0 +1,193 @@
+include <hollow_out.scad>;
+include <archimedean_spiral.scad>;
+
+head_size = 26;
+segments = 3; 
+thickness = 3; 
+spacing = 0.65;
+
+module joint_Y(leng, width, height, ring_offset, thickness) {
+    half_h = height / 2;
+    half_thickness = thickness / 2;
+    
+    inner_leng = leng - thickness * 2;
+    inner_width = width - thickness * 2;
+    
+	// U 
+	linear_extrude(height, center = true) 
+    difference() {
+        hollow_out(thickness)
+            offset(delta = thickness, chamfer = true) 
+                square([inner_leng, inner_width], center = true);
+		
+        translate([-half_thickness - inner_leng / 2, 0, 0]) 
+	        square([thickness, inner_width], center = true);
+	}
+    
+	// ring
+	r = half_h; 
+    offset_x = ring_offset - r / 4;
+    translate([half_h + inner_leng / 2 + half_thickness, 0, 0]) 
+	rotate([90, 0, 0])
+	linear_extrude(thickness, center = true) 
+    difference() {
+	    hull() {
+			translate([offset_x, 0]) 
+                circle(r);
+			translate([-r / 2, 0, 0]) 
+                square([r, height], center = true);
+		}
+		translate([offset_x, 0]) 
+            circle(r - thickness);
+	}
+}
+
+module moving_fish(head_size, segments, thickness, spacing) {
+    joint_leng = thickness * 2;
+    joint_height = thickness * 2 + spacing * 2;
+    joint_thickness = joint_leng / 3;	
+    joint_width = joint_thickness + (spacing + joint_thickness) * 2;
+    ring_offset = joint_thickness / 2;
+
+    module tri_bone(tri_side_leng) {
+        double_spacing = spacing * 2;
+
+        tri_r = tri_side_leng * 0.5773502;
+        tri_r_m1 = tri_r - 1;
+        half_tri_r_m1 = tri_r_m1 / 2;
+        
+        slot_leng = joint_thickness + double_spacing;
+        
+        translate([0, 0, half_tri_r_m1 + 1]) {
+            translate([slot_leng, 0, joint_height / 2 - half_tri_r_m1 - 1])
+            rotate([90, 0, 0]) 
+                joint_Y(
+                    joint_leng, 
+                    joint_width, 
+                    joint_height, 
+                    joint_thickness/ 2 , 
+                    joint_thickness
+                );
+            
+
+            offset_x = (-tri_r - 1 + joint_width) / 2;
+            rotate([0, -90, 0]) {
+                // triangle
+                linear_extrude(thickness, center = true)   
+                difference() {
+                    offset(r = 1) 
+                        circle(tri_r_m1, $fn = 3);
+                    
+                    // slot
+                    translate([offset_x, 0, 0]) 
+                        square(
+                            [
+                                slot_leng, 
+                                joint_height + double_spacing
+                            ], 
+                            center = true
+                        );
+                }
+                
+                // stick
+                translate([offset_x, 0, 0]) 
+                rotate([90, 0, 0]) 
+                rotate([0, 90, 0]) 
+                linear_extrude(slot_leng, center = true) 
+                    circle(joint_height / 2 - joint_thickness - spacing);
+            }
+        }
+    }
+
+    module head(tri_leng) {
+        tri_leng_d2 = tri_leng / 2;
+        tri_leng_d4 = tri_leng / 4;
+        tri_leng_d5 = tri_leng / 5;
+
+        module eye() {
+            translate([tri_leng_d4, tri_leng_d5, tri_leng_d5]) 
+                sphere(tri_leng / 10);    
+        }
+               
+        tri_r_m1 = tri_leng * 0.5773502 - 1;
+        mr = tri_leng_d4 * 0.8660254;
+        
+        translate([0, 0, tri_r_m1 / 2 + 1]) 
+        rotate([0, -90, 0]) {
+            difference() {
+                hull() {
+                    linear_extrude(thickness, center = true) 
+                    offset(r = 1) 
+                        circle(tri_r_m1, $fn = 3);
+                                
+                    translate([tri_leng / 14 * 3, 0, tri_leng_d2]) 
+                        sphere(mr);
+                        
+                    translate([-tri_leng_d4, 0, tri_leng_d2]) 
+                        sphere(mr);
+                }
+                
+                linear_extrude(tri_leng * 1.5, center = true) 
+                translate([-tri_leng / 2 - tri_r_m1 / 2 - 1, 0, 0]) 
+                    square([tri_leng, tri_leng], center = true);
+                
+                translate([0, 0, tri_leng / 1.25]) 
+                rotate([90, 0, 0]) 
+                scale([0.75, 1, 1]) 
+                linear_extrude(tri_leng, center = true) 
+                    circle(tri_leng / 1.5, $fn = 3);
+            }
+            
+            // eyes
+            eye();
+            mirror([0, 1, 0]) eye();
+        }
+    }
+    
+    point_distance = joint_leng + ring_offset + spacing * 3;
+	arm_distance = head_size; 
+	init_angle = 540;
+	num_of_points = segments + 2;	
+    
+    points_angles = archimedean_spiral(
+        arm_distance = arm_distance,
+        init_angle = init_angle,
+        point_distance = point_distance,
+        num_of_points = num_of_points
+    ); 
+     
+    side_leng_step = 0.45 * head_size / segments;	
+
+    // head
+    rotate(init_angle) 
+        translate(-points_angles[0][0]) 
+        rotate(90) {
+			tri_bone(head_size); 
+			head(head_size);
+		}
+    
+    // body
+    leng_pts = len(points_angles);
+    for(i = [1: leng_pts - 2]) {
+        translate(points_angles[i][0])
+        rotate(points_angles[i][1] + 90)
+            tri_bone(head_size - side_leng_step * i);
+    }
+    
+    tail_r = head_size / 3;
+    // tail
+    translate(points_angles[leng_pts - 1][0])
+    linear_extrude(joint_height) 
+    rotate(90 + points_angles[leng_pts - 2][1]) 
+    translate([tail_r / 2, 0, 0]) {
+        difference() {
+            circle(tail_r);
+            translate([tail_r * 0.75, 0, 0]) 
+                circle(tail_r);
+        }
+        hollow_out(thickness / 2.4)
+            circle(3 * thickness / 2.4);
+    }
+}
+
+moving_fish(head_size, segments, thickness, spacing, $fn = 24);
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