30:00 Correction - I think the way Sludge Monster and Toxrill actually work would be Sludge Monster ETBs or Attacks and puts a Slime Counter on ONE creature which turns it into a 2/2. However, Toxrill says slime counters also give things -1-1, so the counter from Sludge Monster not only turns the thing into a 2/2, but it combines with Toxrill and also gives the thing -1-1. So when you end your turn with Toxrill it also puts another slime counter on everything, so the thing that Sludge Monster slimed gets a 2nd slime counter (every other creature just has 1 from toxrill), and the thing that Sludge Monster tagged will die right away when you end the turn with Toxrill (whereas everything else is still at 1/1 because of Toxrills slime counter and Sludge Monsters 2/2 effect).
Man I haven't played magic the gathering in a long time, but I like the vampire decks, this isn't part of this set but one of my favorites is Edgar Markov. He is basically vampire swarm whether he is in play or not.