I like trains refers to a popular catchphrase, originating from the asdf movie series, connected to the I-Like-Trains-Kid, also known as Ryan, who says the line prior to someone getting run over by a locomotive.
“I like trains” was first featured in asdfmovie2, uploaded to YouTube by TomSka on January 1st, 2010.
The line was voiced by Edd Gould, an animator for the asdfmovies, who unfortunately died in March 2012.
“I like trains” was later included in the third installment of the asdfmovie series, published in December 2010.
“I like trains” became truly viral after September 23rd, 2011, when TomSka uploaded the “I LIKE TRAINS (asdfmovie song)” music video to YouTube.
Both the song and the catchphrase itself grew popular among fans of asdfmovies, becoming a submeme, although its popularity started decreasing over the years.
Ryan, or the “I like trains” guy was making a cameo in the anime intro of asfmovie12, which was uploaded to YouTube by TomSka on August 30th, 2019.