I had an idea for a monster Superhero character: Jurasskick.
Originally he was a Meta-human named Sam Sheolkreek.
Power: Fossil Spirit Transformation
While in physical contact with the fossilized remains of an extinct animal he could temporarily mutate individual parts of his body into the likeness of the animal. This transformation could last up to several minutes at a time before reverting but it required that he had a sample of the creatures fossil.
Fossils however are usually hard to find on one's own, fragile, and well protected for study, so he was only able to obtain a few fossil fragments and worked them into a necklace so they would be close at hand. His samples came from:
Therizinosaurus, Carnotaurus, Ampelosaurus, and Kentrosaurus.

Then an accident took place where his powers got disrupted by a villain causing his cells to fully absorb the form of his samples and not reverting back causing him to fully transform into a Mutant Dinosaur Hybrid Monster. He partially retains his human sense of self but his mind and identity is muddled by the spirits of his fossils giving him their ancient memories and instincts. Fortunately 3/4ths of his dinosaurs are Herbivores so he is unlikely to develop a taste for human flesh, but Herbivore does not mean Gentle or Harmless. Those Spikes and Claws are not just for show.