The Mammoth is one of four "Fearful Beasts" released in the Galaxy Warriors toy-line. The other beasts are the Dinosaur, Tiger and Horse. All four beasts are very rare and came packaged in the same box with the title Fearful Beast from Planet Ferror.
It cannot be denied that the Mammoth is cheesy looking, but I think that "cheesiness" adds to the allure of this beast. Many toy-lines have big cats and horses for their characters to ride, but few others, if any, have a mammoth. Once the Mammoth is removed from its box and gets posed with another character, its coolness becomes apparent.
The Mammoth pictured in this post is from my personal collection, and this is the only one I have seen in its original packaging. I only mention this because I am unsure of which Galaxy Warriors came packaged with the mammoth. Mine came with Dino Man, but other figures may have also come packaged with the mammoth. I know that the Tiger in this toy-line was known to have come packaged with three different figures. At this time I cannot say for sure if other figures were offered with the Mammoth beyond Dino Man, but on the side of the box, the mammoth is being ridden by Magnon and not by Dino Man. However, this is not enough evidence to say for certain that any mammoths came packaged with Magnon.
The background painting in the box is very prehistoric and cool. Please be aware that packaging for this toy-line was made from very cheap material. The cardboard used for figure cardbacks and for the beasts' boxes is very thin and bends easily. The Mammoth's body is made from a soft "rubbery" plastic, probably PVC, and it is hollow.
On the Mammoth's belly is the Sungold stamp (see below). That's how you know your Mammoth is "legit".
The Mammoth came with no saddles or accessories beyond its rider.
Did the painting Mammoth (below) by Frank Frazetta inspire Sungold to include a Mammoth in the line? I don't know, but its something to think about. For more information on Frazetta's influences see The Frazetta Connection.