Praise be to Allah.
It is not permissible to taxidermy animals, but that is not because they are images; rather it is for other reasons, including the following:
1. It is a type of folly and a waste of money.
2. It could lead to people putting up images by way of thinking that they come under the same heading as these taxidermied animals.
3. That is a means that leads to becoming attached to this taxidermied animal and thinking that it could ward off harm from the house and its occupants, as some ignorant people think.
This was stated by Shaykh ‘Abd al-‘Aziz ibn Baz (may Allah have mercy on him), as it says in his Fatawa (8/426).
4. The taxidermied animal may be an animal whose meat cannot be eaten, so it is impure (najis), and keeping something that is impure is not permissible, because what is impure must be removed and got rid of.
This was stated by Shaykh al-‘Uthaymin (may Allah have mercy on him), as it says in Liqa’ al-Bab al-Maftuh (no. 14).
Shaykh al-‘Uthaymin (may Allah have mercy on him) pointed out that taxidermied animals do not come under the heading of images, as he said:
But this is not an image, as some people think, as they think that this is like an image that has been made by a human, when that is not the case, because it is the creation of Allah, may He be glorified and exalted. End quote.
based on that, the fact that these taxidermied animals are in the prayer room is not a reason to stop praying in your prayer room. Rather they should not be in front of the worshippers or in a place where they can be seen during the prayer, lest they distract people from the prayer. Similarly, if they are impure (najis), they should be removed from the prayer room.
We should also point out that the prayer room of the school does not come under the ruling on mosques; nevertheless, it should be respected and protected from anything that is not appropriate, out of respect for the prayer that is offered in that place.
And Allah knows best.