Fungus Sliver

Creature — Fungus Sliver

All Sliver creatures have "Whenever this creature is dealt damage, put a +1/+1 counter on it." (It must survive the damage to get the counter.)

2/2

2013-07-01:
Abilities that Slivers grant, as well as power/toughness boosts, are cumulative. However, for some abilities, like flying, having more than one instance of the ability doesn’t provide any additional benefit.
2013-07-01:
If the creature type of a Sliver changes so it’s no longer a Sliver, it will no longer be affected by its own ability. Its ability will continue to affect other Sliver creatures.
2021-03-19:
If multiple sources deal damage to a Sliver at the same time and that Sliver survives the damage, it gets only one +1/+1 counter despite its impressive efforts.