Ptah explaining how words can get him into trouble.
Ptah: "Once, just for fun, I made up the word platypus and..." instantly a duck billed furry thing appeared on the floor scrabbling around in a panic "Oh dear, yes that's exactly what happened."
Set's introduction in Throne of Fire. Apparently, he likes the name "Rockin' Red Reaper" better than "Evil Day". Then again who wouldn't?
In the audiobook version, Carter's "I don't think I could've been more surprised if Bes had said 'By the way, you're leaning against a hydrogen bomb'" because the latter is said in Bes's voice.
The Serpent's Shadow
Shelby is both adorable and hilarious beating the enemy magicians on the butt with her wand and chanting 'Die, die'.
The interactions between Drew and Sadie are this and awesome.
"Sadie, please do not call the Destroyer of Souls 'poochiekins'."
The return of Hindenburg the camel. "If you're confused think how the criosphynx felt."
The chapter where Amos/Set is fighting with Sarah Jacobi. Sadie rushes in to help her uncle, only to be nearly killed by Jacobi, and then Walt/Anubis steps in and takes care of her. The words exchanged between Set and Anubis is just lulzy:
Clearly Sadie is a huge fan, because who else could she be channeling when she tricks the goddess Neith into believing in a jelly baby conspiracy in a display of rapid fire stories half-remembered from a past encounter with her grandfather's veteran friend in the spur of a moment, while deviously scribbling down the glyph for a protection barrier as the sun slowly set towards their victory?