Oh, dude, you're asking about similes now? Like, who even uses those anymore? But hey, if you really wanna know, the items that complete the simile "As limp as a..." could be "wet noodle" or "flaccid balloon." But seriously, who even talks like that these days?
This isn't an idiom. When you see AS___AS___you're dealing with A Simile. This simile is comparing something to a pair of old, patched socks, which would indeed be very limp.
simile its a simile when you use "like"
ANSWER:drowned kitten
Historically, the simile has been "deaf as a door post". *NOTE: Today, these kinds of comparisons would be seen as rude.
fiddle
mule
As dear as salt
Niagra Falls morning.
...mule."
as blue as sea
my teacher was as surprised as a dog
A simile. A simile compares two unlike items and specifically uses like or as in the comparison.