Just think of the Emoji block of Unicode. Perhaps the man 👨 at U+1F468 or the woman 👩 at U+1F469 will suffice, but there are also children, older people, etc. Here’s a list of Emoji People. It still depends on your actual use-case.
If other exotics are no issue, take a look at Egyptian Hieroglyphs. There are lots of human pictograms, like 𓀠 at U+13020 and many others. Another generic (even gender-neutral) pictogram might be the symbol for men’s restrooms 🚹 at U+1F6B9, but a charge for restroom use is not desirable. There’s still more, like the pedestrian 🚶 at U+1F6B6 or the bust in silhouette 👤 at U+1F464.
As comprehensive, yet extensible list:
- 👤
U+1F464BUST IN SILHOUETTE(Block Miscellaneous Symbols and Pictographs) - 👨
U+1F468MAN(Block Miscellaneous Symbols and Pictographs) - 🚹
U+1F6B9MENS SYMBOL(Block Transport and Map Symbols) - 🚶
U+1F6B6PEDESTRIAN(Block Transport and Map Symbols) - 웃
U+C6C3HANGUL SYLLABLE US(Block Hangul Syllables) - ꆜ
U+A19CYI SYLLABLE HLIE(Block Yi Syllables) - ጰ
U+1330ETHIOPIC SYLLABLE PHA(Block Ethiopic) - 𓀠
U+13020EGYPTIAN HIEROGLYPH A028(Block Egyptian Hieroglyphs)
(Use Ctrl++ or off-site styling to distinguish details.)
Depending on platform, the characters might be rendered surprisingly unresembling:
