- oviparity
- oviparous
- ovipositor
- ovoviviparousness
- owl
- owlet
- pachydermatous
- painted lady
- palmate
- palpiform
- palpognath
- palpus-bearer
- ovarian
- ovary
- oven-bird
- oviparousness
- ovoviviparity
- ovoviviparous
- ox
- pachyderm
- oyster
- pallia
- palmiped
- palpulus
- palus
- paddle
- paddlefish
- pallah
- pallium
- palm-cat
- palmated
- palp
- palpal
- palpicorn
- palpocil
- panda
- paradoxure
- parakeet
- pangolin
- panther
- pantheress
- parapodia
- parapodium
- paroquet
- parotic
- parrot-fish
- partridge
- passenger-pigeon
- passerine
- pastor
- pasture
- patagium
- pavo
- peacock
- peafowl
- peal
- pearl-oyster
- pectinate
- pectoral
- pectus
- pelican
- pea-chick
- peahen
- peccary
- pecten
- pectinated
- pectines
- pedal
- pedate
- pedicellaria
- pediculidae
- pedipalpi
- pedipalpous
- peewit
- pelecypod
- penguin
- pentadactyl
- perch
- penvis
- peristome
- perk
- pern
- petrel
- pewit
- phalanger
- perissodactyl
- perissodactylate
- periwinkle
- person
- petaurist
- phalarope
- pheasant
- photospheres
- phyllopod
- pickerel
- piddock
- pie
- pilchard
- pine-carpet
- phyllophagan