A little advice please guys,
Can you amplify a childrens toy by disconnecting the speaker, connecting the leads to a plug and connecting to a amplifier, where a input to the amp would go.
Is this possible or am I way out.
Any help would be great, thanks.....

 

Generally, yes.
You might need a load resistor on the speaker wires to get the voltage down to where the bigger amplifier doesn't be constantly over driven, but just connect it and find out if this is even a problem.

You need a line level input, not a microphone input or a phono input.

 

Cheap childrens toys often use direct PWM to the speaker.

The sound will be much better if you connect to the amplifier input through a series resistor, with a cap to ground. That will smooth the PWM signal back to an analogue sound signal.