The animal tissue that functions in transmitting messages rapidly through the body is nervous tissue.

Here's why:

* Specialized cells: Nervous tissue is made up of specialized cells called neurons, which are designed for communication.

* Electrical signals: Neurons transmit information through electrical impulses called action potentials.

* Speed: These electrical impulses travel very quickly along the neuron, allowing for rapid communication.

* Network: Neurons form complex networks throughout the body, connecting the brain and spinal cord to muscles, organs, and sensory receptors.

Let me know if you'd like to learn more about nervous tissue!