The Tyranto Rex (ボウクンレックス Boukun Rekkusu?) is a Dream Eater that appears in Kingdom Hearts 3D: Dream Drop Distance. Its Spirit version is obtained via Spirit synthesis, while its Nightmare version can be found in Country of the Musketeers and The World That Never Was.
Kingdom Hearts 3D: Dream Drop Distance
The second-or-possibly-first most vicious Dream Eater out there. Put it on ice before it puts you in a tough spot.