- sheat-fish
- sheldrake
- shovelbill
- shoveller
- shrew
- shrimp
- sickle-feather
- shoebill
- shrew-mouse
- shrike
- side-winder
- silk-gland
- silver fox
- simian
- siphon
- siphuncle
- sirenian
- sirgang
- siskin
- skate
- sloe-worm
- sloth
- slow-worm
- skimmer
- skin
- skink
- skipper
- skua
- skunk
- skylark
- sleeve-fish
- snake-bird
- snake-lizard
- snipe
- snow bunting
- snow-bird
- snow-cap
- snow-grouse
- snow-owl
- soil
- smelt
- smew
- slime-gland
- slink
- slip
- sloth-bear
- snake-head
- snout
- sockeye
- solan
- soldier-fish
- sole
- soliped
- somite
- somitic
- song-sparrow
- song-thrush
- sora
- sloth-monkey
- snapper-turtle
- solan-goose
- sow-bug
- sparling
- sparrow
- spearfish
- spermary
- spaniel
- sparoid
- sparrow-hawk
- spatule
- speciation
- speculum
- spectacled
- specula
- sperm-whale
- sphingidae
- spider-monkey
- spineless
- spider-crab
- spikefish
- spinicerebrate
- spinule
- spinulose
- spiracle
- sporozoan
- spot
- springbok
- springtail
- spinuleferous
- spinulous
- spirula
- spondilus
- spoon-bill
- spoor
- staggart
- stalk
- stall
- stall-feed
- stanchion
- staniel