yikes.

Attested from mid-20th century, perhaps derived from yoicks, a hunting call used to urge hounds after a fox, which is attested from 1765–1775, that also is sometimes used as an exclamation of excitement or triumph. Yoicks is perhaps related to the earlier hoicks. Hoicks (alternatively hoick, hoic or hoik) is a variant of hyke, which was used as an exclamation of encouragement to hounds hunting deer. Further etymology unknown. Alternatively, it may be derived from yipes, which is an earlier exclamation of similar usage as yikes (and is often considered to be an alternative form of yikes). Yipes may be derived from yipe, which itself may be derived from the yie sound often used to express pain or dismay, with the -p adding onto it in the same way as yep and nope. Or, yipes may be derived from the yipping sound that dogs make. Or, possibly a conflation of both of the previous.