The Eloi are a bright, happy people, who speak a simple language and are mainly interested in playfulness. They often play with flowers and other amusing items. Physically, they are shorter than humans, have blond hair, smooth skin, and weaker are weeker thwen modern humans. ("The Time Machine: An Invention")
Additionally, they seem to have some form of low grade telepathy. Weena was able to sense The Time Traveler's presence in her mind, and became aware of strong, clearly-imagined thoughts in his mind. ("The Time Machine: A Sequel")
In Other Continuities
The Time Machine (1960 film)
The Eloi in the 1960 movie adaption like dancing and playing in the sun. They also enjoy making constructions with flowers. They have an intense, but almost subconscious, fear of Morlocks and of the dark.
They are fed, clothed, and otherwise cared for by the Morlocks.
The Time machine (2002 film)
In the 2002 movie adaptation of The Time Machine, the Eloi are depicted as identical to modern humans with a hunter-gatherer lifestyle, they have light brown skin and black hair. The apper to shave there heads and tatoo there upper body with tribal paderns, the woman let there hair grow or brad it, possibly this is part of there culture. The former movie version depicts the Eloi speaking modern-day English, a fact which contradicts the original novel and the logical timeline of language evolution. In the latter film version, the Eloi maintain the English language as merely a tradition handed down through generation and intellectual exercise, simulure to modern latin or sandscript, calling it "the stone language or De Lex," as they know of it only from surviving stone tablet inscriptions from our time.