I love Bladeybug and Pythoon so much!
Monsoon - a very heavy fall of mongooses. Or would it have to be Mongsoon?
Rain of Frogs - a storm of biblical proportions
Lightning Bugs - watch out when catching these in a bottle!
Toronado - a spinning funnel of beer, being chased by drunks in an Oldsmobile, and one masked guy brandishing a sword
Les: Monster lizard ravages east coast! Mayors in five New England cities have issued emergency requests for federal disaster relief as a result of a giant lizard that descended on the east coast last night! Officials say that this lizard, the worst since '78, has devastated transportation, disrupted communication, and left many hundreds homeless!
Johnny: Monster lizard?
Les: The wire service never lies!
Johnny: Les, the “B” is out on the printer! It’s monster blizzard!
There’s been a sequel (with CGI shrews!) starring James Best (who also produced) and some of his co-stars from TV:
It’s got a storm (again), but no shrewnami or shrewnado.
As Idle Thoughts stated, the SyFy Channel created a cheesy movie by the name Sharknado, that is, as it sounds, about a tornado that is carrying sharks. They then made a sequel, Sharknado II, which was aired last week during the Discovery Channel’s Shark Week promotional. Thus the recent spate of attention.
Zombie Hyenas!- they eat dead…
…nevermind.
Swansoon!
Zom-Bees.
You may find it amusing to know that while it was Shark Week elsewhere, it was Shart Week on Comedy Central.
I was so glad when that was over. Gad.
Koalalypse: Hungry, and Coming For YOU-calyptus!!!
Flamingo-pires: Pink Because of Their Diet…OF HUMAN BLOOD!!!
**BEAVER-CLYSM: Dam, They’re Scary!!! **
(this one could double as an instructional film for boys entering puberty)
Squizzard!
Baboom: Military scientists turn primates into suicide bombers.
**Gorilla War: ** Jane Goodall teaches her friends in the mist how to fight back.
Pole-Arm Bears: Arctic ursines develop opposable thumbs and the ability to use pikes…
Well, one of the soap opera digest magazines had a recent cover promising a “Shocknado,” which appeared to be either yet more shocking soap revelations or a shark tornado in Brooklyn…
Tortoise Stampedes!
Hurricanary !
**Intercontinental Ballistic Weasels.
Yak-quake!
Elephanteater vs. Sharkadillo.**
Attack of the Cordwainer Birds
edited to add: Well, it is the SYFY Channel. 
Octomom Vs Mecha-Nanny!
Or is that already a show?