The male Inkling player character from the Splatoon series. Their female counterpart is the Inkling Girl.
As of Splatoon 3, all hairstyles are no longer gender-locked. In order to tell apart male and female inklings, the only discernable difference is sometimes just the eyebrows.
As shown in the above examples, male inklings canonically have thicker, longer eyebrows than females. This is, however, subject to the creator's artstyle.
If the gender is not overtly clear, resort to using ambigious gender tags instead.
Splatoon Wiki: Player Settings
This tag implicates inkling_player_character (learn more).