Baruto Kaito had 4 fights in RIZIN and was actually pretty competitive for a guy who weighed in a 400lbs.
He immediately switched to MMA after retiring from Sumo Wrestling, so he was still in his physical prime, which was a big change from the usual washed up Sumo dudes who fought in PRIDE since they were always inactive for a long time before PRIDE or K1 forked in the big bucks to get them in the ring against Minowaman.
Baruto did a fairly good job at repairing Sumo's reputation in MMA, can't deny him that, but you had to be there during his run I suppose; he had LOTS of fans of this here Sherdog.
Then you had the 2 Ssireum rivals giants,
Hong Man Choi
and
Kim Young-hyun
both over 7.2ft and weighing 370/380lbs during their Ssireum (Korean wrestling) rivalry when they were at their peak.
They both have 3 victories over the other, with their final match tying them at 3-3 after 6 matches, and they were big in Korea. They were also both nicknamed "Goliath", which was a tad confusing for casual onlookers.
HMC later added "Techno" to his "Goliath" to help us out (and to be fair, Kim was the original Goliath according to most Ssireum scholars)
Then they both switched to kickboxing since there wasn't much money to be made in Ssireum even at the highest level.
Kim retired after going 2-2 in K-1 in 2007/2008, but Choi the
Techno Goliath would switch to MMA with... mixed results.
After his first loss (to Fedor, so no big shame there) he got a life-saving operation, and he was never able to put on weight like he used to and his iron chin was but a long gone memory.
... also,
Aorigele was fun to watch at
ROAD FC 