Odd One Out

[jakeydoodles]

Which is the odd one out? many thanks in advance.

Bill
Pat
Dinah
Mary Ann
Sam

[Toorak]

Sam

The rest are in Alice’s adventures in Wonderland

[fiction-factory]

There are often several possible answers with this- eg Mary Ann is only one with two names or Bill is only one with an even numbe rof letters.
The Alice one looks a good shout assuming Toorak has identified teh characters correctly (I'm confident he has).
I was thinking along the lines of children's tv programmes- Fireman Sam, postman Pat, Bill (and Ben) but am not sure of the other two.

[Toorak]

All named here:

https://www.cs.cmu.edu/~rgs/alice-IV.html

Except Sam