Link to version where Soldier isn't visible:    • Plushtrap lock tracking  

I will tell you how I did this, it can be helpful in other situations too.

First I recorded Team Fortress 2 Soldier doing things.
I added him & his weapon in the animation set editor as an existing element.
Added Plushtrap Chaser.
Applied universal rig on Plushtrap.
Posed Plushtrap to fit similarly to Soldier’s stance at the beginning.
Locked Soldier’s bones on Plushtrap’s bones (not all of them).
Select Plushtrap entirely.
Drag playhead to full in the motion editor.
I saw if it looked cool.
Ears & jaw individual movement.
Turned Soldier & his shovel invisible.
Spotlight above.

Universally this would probably be more helpful to grasp an item you forgot to lock earlier.