This Kodama turns +1/+1 counters into Sword of the Animists. The mass trample is really going to help that last effect too.
There's a few other niche counter interactions that are cool, too. Liege of the Tangle is probably the most relevant one, since those lands can swing for more lands, and so on. You could do some jank with Triad of Fates, might be fun in commander to include some white/black "modified" dependent cards, if there are any good ones. Aven Mimeomancer gives the creature evasion as well as modifying it. Kaya the Inexorable does something similar to fates. Any level up creatures, like Coralhelm Commander, are modified after leveling up at least once. Arbiter of the Ideal, uh, works. Honestly I have to admit I'm just kind of listing these off now. Oh right, Makeshift Mannequin. Let's see how many more niche interactions I can dig up. Tetzimoc, Primal Death can put counters on your creatures and won't destroy them. Huh. Never considered that before now, that could work I guess. Oh, dunno how I didn't think of this sooner, Thelon and his buddies have fun with this, giving big beefy fungus trample and ramping at the same time.
There's plenty of other niche cases, but these were the ones that stood out the most to me for "unconventional counters". And yeah, most of these are jank, but I LOVE jank.