Reveal Lurking Automaton as you draft it and note how many cards you've drafted this draft round, including Lurking Automaton.
Lurking Automaton enters the battlefield with X +1/+1 counters on it, where X is the highest number you noted for cards named Lurking Automaton.
5/29/2014 For example, if you draft Lurking Automaton as the third card in a draft round and then another one as the sixth card in a draft round, each Lurking Automaton that enters the battlefield under your control does so with six +1/+1 counters on it.
5/29/2014 If a Lurking Automaton owned by another player enters the battlefield under your control, the number of counters it enters with will be based on the highest number you noted as you drafted a card named Lurking Automaton, not as its owner did. Unless you also drafted Lurking Automaton, this will be considered 0.