David Fleetham / Common reef octopus (Octopus cyanea), Hawaii.

Ingo Arndt / Close up of foot and eye of Red eyed tree frog {Agalychnis callidryas}

Ingo Arndt / Close up webbed foot of Kuhl's gecko {Ptychozoon kuhli}

Ingo Arndt / Close up foot of Madagascan day gecko {Phelsuma madagascariensis}

Ingo Arndt / Close up foot of Tokay gecko {Gekko gecko}

Franco Banfi / Humboldt squid (Dosidicus gigas) at night off Loreto, Sea of Cortez, Baja California, Mexico, East Pacific Ocean.

Andy Rouse / Mountain gorilla (Gorilla beringei) baby held by mother, Rwanda

Christophe Courteau / Shore clingfish / Cornish sucker {Lepadogaster lepadogaster} Brittany France

MYN / Paul Harcourt Davies / Horsefly (Tabanus bovinus) close up of male feeding on fennel flower nectar (the females are blood suckers) Lazio, Italy, July. meetyourneighbours.net project

Alex Mustard / 2020VISION / Pair of Common cuttlefish (Sepia officinalis), female in foreground and male behind, note circular mating scars on female caused by the males suckers, Babbacombe Bay, Torbay, Devon, UK, May. Did you k...

Michel Roggo / Brook lamprey (Lampetra planeri) showing sucker, Europe

Stephen Dalton / Gecko (Tarentola sp) close up of feet gripping glass, controlled conditions