Eustace's Love of Animals
Eustace is said to love animals but only when they are dead and pinned to a card for studying. This view of love is ironic because a person who truly loved animals will only want to see them living in their natural habitat and not killed just for the sake of scientific study.
Eustace's Seasickness
Eustace complains in his diary that the ocean voyage is rocky and uncomfortable but writes "it's a good job I'm not sea sick" which is ironic in that he was nauseous and seasick from the moment he boarded the ship before they even set sail. This is an example of Eustace's general irony in his sense of himself.
Caspian's Identity
When the group are kidnapped by Pug, Caspian wants to keep his identity a secret because he believes that admitting to being the King will put him in more danger. This turns out to be ironic as the man who buys him is one of the missing Lords they are looking for and it is admitting that he is the King that ultimately frees the entire group and puts an end to the slave trade.
Caspian's Situation as a Slave
When Caspian is sold first, and separated from the rest of the group, it seems that is is in by far the worst predicament of everyone but this is ironic because he is actually in the best situation having been sold to a loyal subject who is anxious to prove his loyalty again by helping to free the others and to assist in the battle ahead.
Eustace's Views on Others
Eustace's journal is in some respects an exercise in irony as his views on everything are wildly paradoxical and ironic in of themselves. An example of this is his statement that it is "so pleasant to be embarked on a dangerous voyage with people who can't even count right" when of course the irony is that he means it is anything but pleasant and that if they cannot even count correctly then their mission is doomed. Again, ironically, it is Eustace whose calculations are wrong.
