A few solid starting points for DIY animatronics:

Adafruit + SparkFun: Great for beginner-friendly electronics (servos, sensors, microcontrollers).

Arduino-based Halloween projects on GitHub – lots of open-source code for motion + sound effects.

YouTube channels like Make:, Animatronics How-To, and DIY Creature Workshop often show step-by-step builds.

If you want to go deeper, look into Raspberry Pi-controlled props for more complex movement + audio sync.

For something quick and spooky, even a simple PIR motion sensor + servo motor setup can create a fun jump-scare effect.