Your's OTTO

https://github.com/OttoDIY/DIY

Otto_BASIC added functions, gestures or sounds in loop
Otto_avoid Otto will avoid obstacles
Otto_push must change on line 53 Otto.walk(1,1000,-1); to Otto.walk(1,1000,1) to make Otto follow you!
Otto_run will run fast straight forward with this code
Otto_singleladies Dance single ladies by Beyonce
Otto_smoothcriminal Dance smooth criminal by Michael Jackson

It costs less than $15

https://gist.github.com/monhambe

Material:

MINI USB ATmega328P Nano V3.0 (1.99€ / $2.45)
Expansion Sensor Shield Module For Arduino UNO R3 Nano V3.0 (0.85€ / $1)
9gr servo motor (4x2€ / $8.63)
HCSR04 (Robo eyes) 0.72€ / $0.85
wire (0.36€ / $0.45)
buzzer (0.25 € / $0.29)

https://www.aliexpress.com/item/1PCS-Nano-3-0-controller-compatible-with-nano-CH340-USB-driver-NO-CABLE-NANO-V3-0/32684621397.html

https://www.aliexpress.com/item/NANO-I-O-Expansion-sensor-Shield-Module-for-Arduino-UNO-R3-Nano-V3-0/32645527004.html

https://www.aliexpress.com/item/4X-Rc-Servo-Mini-Micro-9g-for-Towpro-sg90-Rc-Helicopter-Airplane-Foamy-Plane-Robot-Car/32584189856.html

https://www.aliexpress.com/item/Free-shiping-HC-SR04-HCSR04-to-world-Ultrasonic-Wave-Detector-Ranging-Module-HC-SR04-HC-SR04/32523466302.html

https://www.aliexpress.com/item/10PCS-10-root-dupont-Wire-Cables-2-54mm-20cm-1P-1P-Female-to-female-for-Arduino/32826089347.html

https://www.aliexpress.com/item/High-Quality-Active-Buzzer-Module-for-Arduino-New-DIY-Kit-Active-buzzer-low-level-modules/32839974693.html

Batteries box
https://www.thingiverse.com/thing:2302659

INSTALL:

Arduino IDE
From windows store
or
https://www.arduino.cc/en/Main/Software#

Atmega driver: CH341SER_WIN or CH341SER_MAC

Program:

https://github.com/OttoDIY/DIY
https://gist.github.com/monhambe

Connections

https://cdn.thingiverse.com/assets/b7/2e/d6/d9/dd/O%2B%2BO_-_InstructionsManual_Portrait_CS6_V02-13.jpg

Optional

Swith or connector
https://www.aliexpress.com/item/10PCS-Lot-high-quality-Electronic-8-8mm-6Pin-Push-Tactile-Power-Micro-Switch-Self-lock-On/32844631159.html

https://www.aliexpress.com/item/1pc-5-5mm-x-2-1mm-12V-3A-DC-Power-Male-Plug-Jack-Soldering-Connector/32815781545.html

Bluetooth HC06 or 05
https://www.aliexpress.com/item/1pcs-HC-06-Bluetooth-serial-pass-through-module-wireless-serial-communication-from-machine-Wireless-HC06-for/32583611885.html

This thing was made with Tinkercad. Edit it online https://www.tinkercad.com/things/0hzMiMeJ1Ll