Puddleglum's Character
Puddleglum is a "worst case scenario" type of person and always looks at the worst possible outcome of any event. This trait makes him sound like he is frightened of everything. His character is ironic because he is actually the most courageous of the three searching for Prince Rilian and often puts himself in harm's way for the benefit of others.
Fear of Freeing the Prince
The children and Puddleglum are frightened to free the Prince from the ropes that tie him to the chair as they are convinced he is in cahoots with the evil Queen and wants to do them harm, which of course would be much easier if he were untied. This turns out to be hugely ironic as he is in fact the person for whom they have been searching, and doing what scares them the most (freeing him) is what actually frees all of them from the Queen's evil.
Moles' and Dwarfs' Work Ethic
The Moles and the Dwarves work harder than anyone else in Narnia. The irony here is that they do not consider what they are doing to be work as they enjoy it, and it therefore does not occur to them that they have the most impressive work ethic of anyone.
Rilian and the Fountain
Rilian's mother was murdered by the serpent by the side of the fountain. Rilian now spends all of his time there seeking out the serpent which is ironic because it should be the place he least wants to be as it is the site of the most traumatic event in his life.
Gnomes Being Above Ground
What the children seek - a way to get above the ground - is what the Gnomes dread, as they feel at their safest when deep, deep underground. The ironic part of this is that nobody is where they want to be because the children are under ground although not deeply but far more deeply than is safe for them. The Gnomes on the other hand are under the ground but far too near the surface for them to be comfortable or happy.
