I can't say for certain on all of 'em but some are casters.
I charmed one the other day (only pet available for doing named at end -- blue con when my pet had an "accident" on the way there...)
It came with SoW and a couple other buffs (shammy style).
WHen I charmed it and sent it in, it's first action was to cast Balance of the Nameless thus fully debuffing and freeing itself from charm.
3 guesses what happened to group -- first 2 don't count.
Anyhow thought I'd pass this along to you...