A Unity 3D  scene was created with some landscape and trees. I got the dinosaur asset, including its animations, from an existing project: https://hackaday.io/project/7024-augmented-reality-and-dinosaur-movement-control The following screenshots illustrate the Unity environment.

Currently, the environment contains simple animations: one dinosaur with one looping animation and the camera moving around the dinosaur. There is no audio at the moment.

The application is then deployed for VR on a phone, at the moment I am using Daydream from Google on Android as a target platform: https://vr.google.com/daydream/

This is the Daydream headset used.

An idea for deployment, if this was for the general public, will be to use instead a VR cardboard headset: https://vr.google.com/cardboard/ I noticed, for instance, the science museum sells branded VR cardboards: https://shop.sciencemuseum.org.uk/exhibition-ranges/wonderlab-collection/wonderlab-light/science-museum-virtual-reality-goggles.htm These headset use the same Unity plugin, so the deployment should be straightforward.

Google cardboard specifications are open, so it is also possible to create projects around people creating their own personalised VR headsets. Here is a plan of the VR cardboard parts:

In order to create a set of dinosaur faces to attach to the headset, a suggestion will be to use a light laser cut version. I tried one with 100 GSM paper on a digital cutter.

It is possible to create various shapes (there are published algorithms to create these from 3D models) in order to provide as attachments for the cardboard if the kids wanted these.