The triffid is a fictitious tall, mobile, prolific and highly venomous plant species, the titular antagonist in John Wyndham's 1951 novel The Day of the Triffids and Simon Clark's 2001 sequel The Night of the Triffids. Triffids were also featured in the 1957 BBC radio dramatization of Wyndham's book, a considerably altered 1962 film adaptation, a more faithful 1981 television serial produced by the BBC, and in a 2009 two-part TV series also produced by the BBC.