"Ivan the Space Biker" is the nickname for Gordon Freeman's original character model.

Designed by Chuck Jones, this version of Gordon had a full, wild beard that made him look like a typical biker, as well as a bulbous grey-green HEV Suit (with "Research" written on the back) that resembled a space suit, hence the nickname of "Ivan the Space Biker". He also had a flattop haircut and no glasses. The beard was heavily reduced to eventually turn into the current Gordon's stylish goatee. Of note is that he already had brown hair and green eyes. The model, "doctor.mdl", can still be found in the Half-Life game files, but it cannot be opened.

Ivan's nickname may have been inspired by German singer Ivan Rebroff's likeness, or simply because he has clichéd Russian features with a clichéd Russian first name, or a clichéd Hells Angels / biker look.

Ivan has a cameo appearance in the web comic Concerned.

In Team Fortress 2's Offline Practice mode, one of the bots bears the name "Ivan the Space Biker".