Snow?

snow.R

snow <- function() {
  w <- getOption("width")
  flakes <- c(rep(" ", 10), "*", " ", " ", "*", "❄︎", "❅", "❆")
  
  falls <-
    vapply(1:50, function(x) {
      paste0(sample(flakes, size = w - 10, replace = TRUE), collapse = "")
    }, FUN.VALUE = "")
  
  panes <- lapply(1:50, function(x) {
    paste0(c(rev(falls[seq_len(x)]), rep(strrep(" ", w), 50 - x)),
           sep = "\n", collapse = "")
  })
  
  repeat({
    for (i in seq_along(panes)) {
      Sys.sleep(1)
      cat(panes[[i]])
    }
  })
}