Got a valid answer I think no one will be able to top:
The fairy called Glitter, from Kidd Video -- WHEN she's got a cold.
Believe it or not, this little helper of the group on their cartoon show (and presumably in their comic, if they had one) got deus ex machina super strength
... whenever she sneezed.
Yeah, I don't know what the writers were smoking, either, but it's true.
It would last for a little while, then Glitter would go back to normal again, possessing only the strength of a run-of-the-mill fairy like Tinkerbell, I suppose (however strong that is). Until Glitter sneezed again. Whereupon she would become unimaginably strong again. There was an episode where Glitter lifted the altered tank-sized/spaceship-sized "Kidd-Mobile" to get the young teens back on the road, various episodes where she would power through machines or traps imperiling the group and save them, and even one where she hefted a skyscraper, and used it to drive another skyscraper, many stories tall, into the ground like a tent peg.
The most convincing display, in conjunction with the above, is probably the following, where, to the amazement and delight of her group, she breaks and COMPRESSES open a steel vault.