Spyro the Speech Controlled Quadropod was initially created by me in highschool using DAGU's quadropod design. Several years later while studying at Purdue, I upgraded it with a speech recognition module allowing it to sit, stand, wag its tail, or play dead using just your voice.
The Instructables link has a complete write-up about how to create such a robot from scratch. The speech recognition is actually done on my computer. Bitvoicer does the heavy lifting for speech-to-text processing and the transcribed commands are sent to the robot via a HC06 Bluetooth module.