Over the Fence, usually stylised as Oh no, look who's OVER THE FENCE, was a strip in The Beezer and Topper, first appearing in issue 106 (26th September 1992). It was drawn by Jimmy Hansen.
It revolved around two kids called Eric and Lucy who lived next door to each other and hated each other's guts, and so the stories often involved them menacing each other in over the top ways, although their (single) parents were oblivious to all of this.
Over the Fence went on to appear in all but ten issues of the comic after its debut, though it only ever had one appearance in full colour (issue 119, 26th December 1992). It did not jump ship to The Beano or The Dandy when the comic closed in 1993, but a similar strip appeared in The Dandy later that year called First Class (which was largely the same concept except it involved four kids instead of two, and moved the strip to a school setting)