While you could obviously just throw an ancient white dragon on your poor players, wouldn't it be way more fun if it were an unassuming critter that turns out to be really strong? Like, high double digit CR strong?
Imagine this. Your players are walking through an orphanage (it is probably Shivaska's child prison because they're high-level and all, but whatever) when suddenly they hear a terrible pluck sound, followed by a high pitched scream and the buzzing of a pair of diminutive wings. Being well versed veterans they immediatly assume (correctly) that it is a tooth fairy and, being mythic veterans, shrug it off and go on helping that poor child. What they don't know, however, is that this is The Tooth Fairy (with a capital T) - Shivaska's personal pet who is a 20th level rogue and very, very fond of mythic teeth.
Or how about this. The players, traumatized but alive, are now walking through some forest (maybe to request the favor of a dryad or something) when they hear steps on the forst floor. As soon as they see three small canine faces they recognize the pugwampi, the ultimate stall troll (at least for 3rd level mooks, that is. They are mythic heroes). Knowing the aura of failure that surrounds these guys they refrain from doing anything that involves luck such as attacking them, preferring to utilize no-save spells. However, they find that even seemingly luckless tasks tend to fail (they can't seem to remember where they've put the spell component pouch, someone sneezed during the spell and they missed the last syllable) - all because these are the actualy the three advisors of the local Glaistig, who is known to despise trespassers.
What are some of your ideas to boosted critters?
PD
you mean, things like winged, fire breathing kobolds?
That's a cool idea! Great disciple of Dahak who's actually a "measly" kobold (dragon disciple 10)... I like!
Kobold ninjas. They were a variation on Tucker's Kobolds, but, y'know, they were also ninjas. This was back in 2e, though. The mid-level PCs thought they were just going up against a bunch of regular kobolds. Boy were they surprised!
Even just regular Tucker's Kobolds give me nightmares. Having pimped Tucker's Koblods? Bye.