Homarid enters the battlefield with a tide counter on it. At the beginning of your upkeep, put a tide counter on Homarid. As long as there is exactly one tide counter on Homarid, it gets -1/-1. As long as there are exactly three tide counters on Homarid, it gets +1/+1. Whenever there are four or more tide counters on Homarid, remove all tide counters from it.