Crawlers are spider-like alien enemies that are encountered in the first Contra game, and the game's remake. They also reproduce and spawn from egg hatches. They are known to appear during the boss battle with the Alien Heart. They also reappear in the NES version of Super Contra in the 7th level, hatching from egg hatches again, but they are much smaller though, and the hatches work faster too. A different enemy seen in the level, spitting large bullets at the players, might be related to the Crawler species. In Operation C, an similar enemy encountered in an alternative form where they pop open to release 3 crawlers that hound the player. However, they appear in almost every game or installment of the Contra (series) since then.