Ivy Lane Denizen similar effects
Gatherer is quite a powerful search tool if you know how to use it.

Even a good search will probably pull up lots of useless cards, but a page or two of results is easily searchable (I recommend using Visual Spoiler mode, it makes it a lot easier to quickly scroll through, in my opinion), and some of the cards that don't do quite what you're looking for may be useful anyways.

Here is my search:
Colors: Red, Black, Blue or Colorless (exclude all other colors)
Text contains: "enters the battlefield", "counter", "creature", "+1/+1"
Text does not contain: fabricate, bloodthirst, devour, evolve, modular, sunburst

I chose my search terms to closely match what you were interested in, and filtered to avoid the +1/+1 counter related mechanics that were not interesting but cropped up frequently in the results.  

This resulted in 89 results.  Most of them are not particularly useful, but it does pull up the Graft creatures in blue, and Sage of Fables, Oona's Blackguard, and Olivia, Mobilized for War which are all along the lines that you were looking for, albeit more limited in scope.  It also pulls up a bunch of creatures that enter the battlefield with +1/+1 counters which may be interested although not what you were looking for.

The dangers of searching this way is that you get exactly what you ask for.  This search does not, for example, pull up Mikaeus the Unhallowed, because the wording of the Undying reminder text is "When this creature dies, if it had no +1/+1 counters on it, return it to the battlefield under its owner's control with a +1/+1 counter on it." This text misses the "enters the battlefield" search term I was using, and therefore a new search would be needed in order to find it.