- tergal
- tern
- terrestrial
- test
- testaceous
- testacious
- tetradactyl
- tetradactylous
- tether
- tetrapod
- thousand-legs
- threadworm
- thoracic
- thrasher
- tibiae
- tiger-cat
- thorax
- thornback
- thresher
- throstle
- thrush
- tibia
- tick
- tit
- titlark
- titling
- titmice
- titmouse
- tittlebat
- tod
- topaz
- tope
- torpedo
- toxiferous
- tortoise
- toque
- torporific
- torquate
- toucan
- trainer
- transhumant
- tree-toad
- trepang
- triangulate
- trichina
- trichinae
- triclad
- tridactylous
- trigonal
- triple-tail
- trod
- trout
- tread
- trematoda
- tuna
- tunny
- turbit
- tribe
- trichomonad
- tridactyl
- trochal
- trodden
- triton
- trochophore
- troglodyte
- trumpeter
- trunkfish
- tsetse
- tup
- turbot
- turkey
- turkey buzzard
- turreted
- turtle
- tush
- tzetze
- turtle-dove
- tusk
- tusker
- twite
- two-spinous
- umbrella
- undercoat
- undergrowth
- ungulae
- ungulate
- unicorn
- unicorn-fish
- unfledged
- ungual
- unguiferous
- unguiform
- ungula
- unicorn-whale
- uniparous
- unring
- urogenital
- untrained
- urchin
- valve