Most complex hat-trick was spread across 3 overs, 2 innings
The most complex hat-trick in Test cricket was completed by Australian pacer Merv Hughes on December 4, 1988. The bowler took a wicket with the last ball of his 36th over and dismissed West Indies' last batsman with the first ball of his next over. He completed his hat-trick with a wicket off the first ball of the second innings.