The LEGO Marvel Super Heroes Seasonal theme (Advent Calendars) are annual LEGO sets released offering a countdown to Christmas. Each set includes 24 small builds, one to be opened and assembled each day from December 1st to December 24th. The calendars typically feature minifigures, tiny vehicles, and festive-themed items, providing a daily Marvel LEGO themed surprise in the lead-up to Christmas.
The LEGO Marvel Super Heroes theme is based on the characters created by Marvel Comics. Originally Marvel was a subtheme of the LEGO Super Heroes theme but was later separated into its own theme. Over time, sets in the Marvel Super Heroes theme includes most characters and situations released to the marvel Universe from films to the comics to TV series.