Animating something enormous convincingly is harder than animating something human-sized. Shadow of the Colossus, released in 2005, remains one of the clearest examples of large-scale creature animation done well. Team Ico used secondary animation layers extensively: the colossi had fur, loose stone plates, and body fat that all moved independently from the primary skeleton. When Valus, the first colossus, took a step, the ground shook and his beard swayed on a separate simulation pass.
The team also deliberately slowed the animation curves for large movements. A human character punching takes roughly 8 to 12 frames to complete the action. Valus swinging his arm took 30 to 40 frames. That timing difference is what made him feel heavy rather than just large. Freelance animators often miss this because the instinct is to speed up animations to avoid them feeling sluggish.
The secondary motion was achieved through a combination of cloth simulation and hand-keyed secondary bones. Modern equivalents in Maya or Blender use nCloth or soft body dynamics for similar results, but the underlying decision, which parts of the creature move independently and at what delay, is still a manual artistic choice.
When you receive a brief for a boss character or large creature rig, ask specifically about secondary motion expectations. A rig with full secondary bone chains takes longer to build and longer to animate. Quoting without that clarity is a common way freelancers undercharge on creature work.