Memory Leaker

Whenever another creature with toughness 4 or greater enters the battlefield under your control,
put a Heap counter on Memory Leaker.
Workload 4 — At the beginning of your upkeep,
if Memory Leaker has four or more Heap
counters on it, remove those counters. If you do,
up to X target lands you control become 4/4
Garbage creatures with trample, where X is the
number of counters removed this way. They're
still lands.