Timid Soul, aka Caspar Milquetoast).
With Doll Man, it is when he becomes small that he becomes a big man, if you know what I mean. Since she has obviously not read the book on superhero behavior, the librarian cannot know Darrell is Doll Man, so she cannot know he is just pretending to be a coward.
This brightly colored, beautifully illustrated entry into the Doll Man series is from Feature Comics #47 (1941). There is a discrepancy with the Grand Comics Database for the artwork credits. Quoting the indexer notes: “According to Lee Boyette in Alter Ego #90, Fran Matera sneaks his initials into panels on pages 5 and 7. According to Jim Amash, in the Quality Companion, and who had done an interview with Matera, he states this art is by Reed Crandall.” I’m siding with Jim Amash on this one.