Depends on the species, but most get relatively large. The Asian Tapir can reach 7+ feet and 700+ lbs, which could easily be confused for a baby elephant or hippo on a grainy youtube film.
It's almost a certainty that the snake is an Anaconda (at least to me, but it is late) which would suggest a Lowland Tapir. As adults they can still hit the 600 lb mark, so that's my uneducated guess.