Poptropicans are small, human-like people who can run fast, jump high, and swim. Their heads float slightly above their bodies, similarly to a bobblehead. Virus Hunter Island reveals that Poptropicans do have necks.
Poptropica Worlds changes the design of Poptropicans to look more like normal humans, giving them visible necks and more realistic proportions. These Poptropicans wear shoes at all times.
Many toys, wallpapers, and other evidence seen on islands prove that Poptropicans, when not shown with simple circular hands, have four fingers. This is supported by the fact that Poptropicans have fingerprints (Spy Island, Mystery Train Island), and the fact that Joe Stockman has visible fingers on Virus Hunter Island. However, Back Lot Island and a Pop Quiz, it is mentioned that Poptropicans do not have thumbs. It may be possible that while Poptropicans have fingers, they lack opposable thumbs.
- Poptropicans are able to withstand immense physical pain, including getting electrocuted (Super Power Island), jumping off tall buildings (Super Power Island), and surviving major crashes (Cryptids Island).
- Poptropicans seem capable of squeezing into tight spaces (Wild West Island) and are flattened when compressed (Lunar Colony Island, 24 Carrot Island).
- Poptropican ghosts do exist, as shown on Ghost Story Island and Nabooti Island. They appear similar to normal Poptropicans, but they glow and are slightly transparent.