A colossal dragon cups his "hands"

[Aaron]

In the last session the party wizard casted time stop, shapechanged himself into a colossal dragon, and asked me if he could "cup his colossal hands" around a medium sized NPC.

He wanted to make him "trapped" without touching him, in accordance with the "other creatures are invulnerable to your attacks and spells" clause of the Time Stop spell.

How would you handle this?

 

[S'mon]

I'd let him cup his hands around the NPC. NPC might conceivably be able to wriggle out of the 'cage' though, probably use opposed rolls.

 

[Celebrim]

How would you handle this?

Readied action to grapple opponent. Opponent is flatfooted against the readied action (loses dex bonus, loses threat zone) owing to the surprise of finding the PC has suddenly shape-changed into a dragon and suddenly cupped his hands around him. Opposed grapple check still required, though unless the opponent has prepared for a situation like this (hello, Freedom of Movement), chances are that will be pretty trivial.

PC has just cast two of the most potent spells in the game. Expect brokenness to ensue.

 

[Grogg of the North]

You could also treat it like a grapple check but the dragon takes the -20 to his check to not be considered grappled himself.