Instructions for the Imaginext T-Rex Mountain

The Fisher-Price division of the Mattel toy company produced the Imaginext System T-rex Mountain play set between 2005 and 2010. This Imaginext building toy is a prehistoric setting for children to snap together by following pictorial instructions. The assembled Imaginext play set makes room for imaginary play with dinosaur and cave dweller action figures. The set includes some parts for a supervising adult to assemble before turning it over to a child. A child can reconfigure the rest of the pieces for additional building fun at any time.

Push the raised tabs on the backs of the upper and lower skull pieces into the fitting holes on the frame piece. Insert the screws into the back of the frame and tighten with a Phillips screwdriver. Stop turning the screws as soon as the heads meet the frame to avoid cracking the plastic pieces.

Loosen the screw holding the battery compartment door on the inside of the upper skull piece. Install three AAA batteries to power the sounds and lights for the T-rex mountain set. Replace the door and tighten the screw.

Work with your child to snap together the pieces of the mountain setting for the initial assembly. Follow the pictorial directions inside the Imaginext building toy to assemble the configuration shown on the label of the box. Step in to aid your child only when necessary to follow the instructional diagrams.

Reach in under the upper jaw of the skull piece and slide the switch to the on position marked by a black filled in circle to activate the lights and sounds on the Imaginext play set.

Push one button on the top of the skull to light the eyes and make jaws move. Push the button next to it make the eyes glow and sound the chomping noises. Push the claw button at the base of the mountain to make the claw drop and trap action figures. Push the button next to the tree to make it fall over.


Encourage your child to take the mountain setting apart after using it as a play set and reassemble the Imaginext building toy in another configuration. The pieces snap to each other on several sides for children to create different shapes for the T-rex mountain.