Sixth Hero Formidable Mecha

UPDATED 7/8/14
Notice how the zords or mecha of the sixth heroes have been super strong animals or vehicles? This of course goes with the Sixth Ranger being stronger than the five and then being weaken half-way. Batman donned the motif of the bat to strike fear into his enemies, so I think that goes hand in hand with the sixth Ranger, they had to have something big and fearsome to fight against their foes.

Dragon Ceasar (Zyuranger) / Dragon Zord (MMPR)
The first Sixth Ranger to have a mecha, a giant dragon is hard to ignore. It needed three more zords to make a robo.

Won Tiger (dairanger) / White Tiger Zord (MMPR)
Little Kou had a big robot to fight with. Kou was the first to have a mecha to become its own robo. Tommy also got the Falconzord in the third season, the falcon was not that big but bigger than the other ninja zords. In Kakuranger, it didn't belong to the sixth hero, there was no sixth hero.

King Pyramider (Ohranger) / Pyramidas (Zeo)King Ranger and the two Gold Rangers had a big honking pyramid.

Artillatron (Turbo)
Phantom Ranger was a sixth Ranger but VRV Master was not. Anyhoo, Artillatron was big and un-ignorable.

Mega Winger (Megaranger/PRiS)
Mega Silver/Silver Ranger get a big wing shuttle. They were the second sixths to have a mecha to become its own robo.

GoTaurus (Gingaman) / Torozord (Lost Galaxy)
A huge bull, its not like its a small cow. It belonged to the two BullBlacks in Gingaman and Torozord belonged to the two Magna defenders. It was the first to need the hero inside to make a robo.

Max Solarzord (Lightspeed Rescue)
In Go Go V, the Linerboy didn't belong to a sixth Ranger as there wasn't a sixth ranger. Linerboy was un-manned, it was re-purposed for the Titanium Ranger as the Solarzord because the Titanium Ranger was original to Power Rangers. It was a big space shuttle. Titanium was the third sixth Power Ranger to have a zord that become its own megazord.

V-Rex (Timeranger) / Q-Rex (Time Force)
Time Fire and Quantum Ranger had a big giant Tyrannosaurus that became a even bigger robot. Time Fire was the third and Quantum was the fourth sixth hero to have a mech become a robo.

Gao Wolf (Gaoranger) / Wolf (Wild Force)
Small, but fierce, he was the same size as the Tiger and Shark. It was the second Sixth Ranger zord that needed two or three more to make its robo but the first that owned all three (not like dragon & Kiba Rangers).

Tenkujin (Hurricanger) / Samurai Star (Ninja Storm)
A giant bird/helicopter. Shurikenger was the fourth and Green was the fifth sixth hero to have a mech become a robo.

deka Bike Robo (dekaranger) / Omega Megazord (SPd)
A bike is not that scary and this robo wasn't that big. Break was the fifth and Omega was the 6th sixth hero to have a mech become a robo.

Travelion (Magiranger) / Solar Streak Megazord (Mystic Force)
The sixth hero got a large big honking train. Shine was the sixth and Solaris Knight was the 5th sixth hero to have a mech become a robo.

Siren Builder (Boukenger) / Flash Point Megazord (OO)
A big red fire truck combined with two other little mecha for Bouken Silver / Mercury Ranger. He was the second sixth to own 3 zords to make his own robo.

Saidain (Gekiranger) / Rhino Steel Zord (Jungle Fury)
Even though not technically a sixth ranger, many fans consider GekiChopper/Rhino Ranger a sixth with its huge Rhino.

Toripter (Go-Onger) / Zord Series Gold (RPM)
A chicken? Well, the only not so formidable animal to be for the sixth Ranger. I think its great it was a chicken. Sentai does like mixing it up a little. The toy was called a falcon but it was referenced to being a flying chicken in RPM. He was the fourth Sixth to need other zords to make a robo.

Daikai-Oh (Shinkenger) / Clawzord (Samurai)Shinken Golds mecha is a huge lobster. Lobsters usually aren't the most fearsome creature in the sea but this one is! Shinken Gold was the 7th official sixth hero to have a mech become a robo.

Gosei Ground (Goseiger) / Gosei Grand Megazord (Megaforce)
Gosei/Robo Knight becomes Groundlion/Lion Mechazord. It is a strong and big zord. The Megazord itself is strong as well.

Gouryujin (Gokaiger) / Q-Rex Megazord (Super Megaforce)
The dinosaur form is pretty strong and big and so is its Megazord form. It is blue while the hero is Silver, belonging to GokaiSilver/Silver Super Megaforce Ranger.

Buster Hercules (Go-Busters)
 BC-04 Beetle and the SJ-05 Stag Beetle are not as big as Gouryujin but they look very technical and strong. When forming Buster Hercules, it looks pretty awesome. They belong to Beet Buster and Stag Buster.

Pteragordon (Kyoryuger) / (Dino Charge)
Pteragordon is bigger than past Pternandon. Pteraiden-Oh is pretty strong. They belong to KyoryuGold/Gold Ranger.

BuildDai-Oh (Toqger)
Belonging to ToQ-6, it looks big and strong.