Boot Nipper

Creature — Beast

Produces: anything getting a counter.

Cares about: nothing.

Partners

3,799 cards can cause anything getting a counter.

1. Shang-Chi and the Ten Rings — When Boot Nipper gets a counter, Shang-Chi and the Ten Rings draws you 5 cards
2. Flourishing Defenses — When Boot Nipper gets a counter, Flourishing Defenses makes a token
3. Ant-Man, Colony Commander — When Boot Nipper gets a counter, Ant-Man, Colony Commander makes a token
4. Obelisk Spider — When Boot Nipper gets a counter, Obelisk Spider costs each opponent 1 life
5. Caradora, Heart of Alacria — When Boot Nipper gets a counter, Caradora, Heart of Alacria puts that many plus one counters on something

1 other cards ask for it too, equally specific. The ones shown are the best connected.