Next time the boss says a trained monkey could do your job, be afraid.

I think a trained monkey would do just as well.

I am just a trained monkey, jumping to everyone's tune.

Prior to the 20th century, it was common for buskers to use a trained monkey as a bottler.

The crowd that witnessed the demonstration made outrageous claims about the workings of the boat, such as magic, telepathy, and being piloted by a trained monkey hidden inside.