weak as a baby

*weak as a baby

 and *weak as a kitten
Cliché [of someone] physically very weak.(Also: as ~.) Six weeks of illness left the athlete as weak as a baby. John is as weak as a kitten because he doesn't eat well.
See also: baby, weak
References in classic literature ?
When the worst was past, and Bunster lay convalescent and conscious, but weak as a baby, Mauki packed his few trinkets, including the china cup handle, into his trade box.