I’ve been looking at images of Ultimasaurus. It says it’s a hybrid between Rex+Raptor+Triceraptops… but where did the clubbed spiked tail come from???
That’s some Stego and probably Ankylosaurus in there!
So maybe… this UNIQUE hybrid could be from:
Trykosaurus + Utasinoraptor
Trykosaurus is a mix of T-Rex and Ankyntrosaurus.
Ankyntrosaurus is a mix of Ankylosaurus + Kentrosaurus which has a spiked tail like Stegosaurus).
And Utasinoraptor is a mix of Sinoceraptops (which is not Triceraptops, but close enough) and Utahraptor (which is not Velociraptor but again, close enough).