bug (n.) 1
bogey, bugbear, imaginary terror
3H6 V.ii.2 [Edward to himself] Warwick was a bug that feared us all
Ham V.ii.22 [Hamlet to Horatio] such bugs and goblins in my life [i.e. terrors and dangers]
TS I.ii.208 [Petruchio to Gremio, of fearing Katherina] tush, fear boys with bugs!
WT III.ii.91 [Hermione to Leontes] The bug which you would fright me with I seek