Animalisms
From Wittypedia
As tired as a badger on day shifts
As welcome as an otter
As tame as a snail
As well to do as money spider
As true as goat
As soft as lemmings landing
As warm as a kangaroos back pocket
As reliable as a half past cockerel
As well meaning as a whale masseuse
As green as a stick insects mascara
As drunk as an amoeba
