14 cards where the full Oracle text includes “formidable —”

Atarka Beastbreaker (Dragons of Tarkir #174)
Atarka Pummeler (Dragons of Tarkir #129)
Circle of Elders (Dragons of Tarkir #176)
Crater Elemental (Dragons of Tarkir #132)
Dragon-Scarred Bear (Dragons of Tarkir #183)
Dragon Whisperer (Dragons of Tarkir #137)
Gimli's Reckless Might (Tales of Middle-earth Commander #494)
Glade Watcher (Dragons of Tarkir #188)
Lurking Arynx (Dragons of Tarkir #192)
Sabertooth Outrider (Dragons of Tarkir #152)
Shaman of Forgotten Ways (Dragons of Tarkir #204)
Stampeding Elk Herd (Dragons of Tarkir #208)
Surrak, the Hunt Caller (Commander Masters #326)
Ultra Magnus, Tactician // Ultra Magnus, Armored Carrier (Transformers #15)
Ultra Magnus, Tactician // Ultra Magnus, Armored Carrier (Transformers #15)

This search is finished. Now the real work can begin.