Depthshaker Titan enters and animates any number of your noncreature artifacts into 3/3 attackers, which you then sacrifice at the end step
Krark, the Thumbless leads to funny, coin-flippy games, at least until you bust out cards like Spark Double and a partner commander like Sakashima of a Thousand Faces to start breaking things
Not quite a changeling is the full-party of Tajuru Paragon that literally says it counts as five total creature types
For two mana, you get a 1/3 Lizard Rogue that deals damage to every opponent each time you bring a creature into play
+1/+1 counter decks are a natural archetype to add this to, but its also fantastic in superfriends decks and even decks using charge counters or -1/-1 counters
Fortunately, it looks like Azurite Sea is just going to take things up a notch