Small tree frogs - Animal flagged. Charmable. level 46. You can dire charm em or regular charm em, but regular charm would kind of be a waste. Great dc pet for a druid, but chanters should leave em alone because there is other stuff for us in PoV to DC.
Other tree frogs - Animal flagged. Charmable. level 60 to 62. Not dire charmable but druid can charm em at high levels. Chanters should have no problem as well. Fairly decent magic resist and SOME are immune to snare/root. They also agro on any illusion, but that doesn't matter when charmed. If you normal charm them and they break, they chain agro the other 2 that are near the outer camp, so they're a bad idea there.
Generally, when doing outter, the mobs you pull out are better charm candidates, mainly because they have lower MR and generally hit a little harder. Plus, when frogs break charm, they aren't as easy to target, and sometimes people only notice the charm breakage when people start dying.
I generally think that getting beat up by a frog is embarrassing, so I don't charm them.