In my Jade Regent campaign I have a scenario in mind in which the Ninja PC needs to sneak past a sleeping Remorhaz.
Remorhaz' have tremorsense. Any advise on the type of skill check and difficulty?
"Light Steps (Ex): At 6th level, a ninja learns to move while barely touching the surface underneath her. As a full-round action, she can move up to twice her speed, ignoring difficult terrain. While moving in this way, any surface will support her, no matter how much she weighs. This allows her to move across water, lava, or even the thinnest tree branches. She must end her move on a surface that can support her normally. She cannot move across air in this way, nor can she walk up walls or other vertical surfaces. When moving in this way, she does not take damage from surfaces or hazards that react to being touched, such as lava or caltrops, nor does she need to make Acrobatics checks to avoid falling on slippery or rough surfaces. Finally, when using light steps, the ninja ignores any mechanical traps that use a location-based trigger."
If you are 6th level, this may be of use, though it's up to your GM how the ability interacts with tremor sense.
Well aside from going around the thing, jumping or running by are really his only options and as mentioned Lights Steps might make one invisible to termorsense during the movement. Depends on GM ruling.
Alot depends on the resources availible too.