THE COMICS RESOURCE

[Helmo]

apparently clifford is a better fighter than articuno

The pokedex lists Articuno as 5 feet tall.

In the opening theme of the Clifford animated series, Clifford, when fully grown, is shown to be at least the height of the Elizabeth family house.

The average height of a one-story house is 15 feet - 8 feet living space + a 7 foot roof. The Elizabeth family's house is two stories (as shown in the cartoon opening, once again) - 16 feet living space + a 7 foot roof (estimate).

Clifford is approximately 5 times Articuno's height, give or take. Though Articuno has the ability to fly, if Clifford catches it, the legendary bird is as good as a chew toy!

EDIT: Going to also point out that Clifford likely has a mass of fur large enough to protect against Ice Beam and such

/applying logic to children's entertainment

Clifford is a giant VISZLA breed dog, a breed VERY SUSCEPTIBLE TO COLD do to a lack of undercoat.

Articuno can make it snow merely by flapping it's wings, plus ice beam can still freeze larger or warmer creatures. Articuno has many other moves besides ice beam and fly too.

If we grant him mind reader and sheer cold it's most powerful moves then Clifford is as good as a dogsicle...

The show is not canon.

Dragonite has a base speed of 80 and can circle the globe in 16 hours. Articuno has a base speed of 85, it is quite unlikely that Articuno would get caught.