Here is a stab at modelling one of my favourite beasties.
Psittacosaurus was a genus of small herbivorous dinosaurs from the early Cretaceous that was part of the group that later included the ceratopsians, which included larger animals like Triceratops. The cheek spikes represented in this toy was one of the features retained by the later ceratopsians. The facial horns and the pronounced neck frill were changes that developed later in the Cretaceous.
The fossils have been found with a quiff of fibres on the tail, which adds to the appeal of the animal, but different reconstructions of it put the quiff in slightly different positions along the tail. You can put the quiff closer to the end of the tail although this makes sewing up the tail a bit more tricky.
50g of Aran in a main colour, a few metres of contrast Aran and some odd DK yarn will produce this little fellow.