You have quite a few missing though - but thats to be expected really as there are hundreds and hundreds of obscure ones out there
This is a narrow sweeper card that could blank if your opponent doesnt have the right creatures on the battlefield, but could also provide a lot of value against a battlefield full of large creatures
himself is honestly kind of bland, just a furry giant ogre giant thing, until you look at his earrings and realize that he's got two gigantic double-digit stat animals -- a Polar Kraken and a Phyrexian Dreadnought -- as earrings
If the deck wasnt a known quantity when Karlov was printed, I dont know that they would have made the same impact, but I certainly think the card is a hidden gem
Second, we actually have huge, expensive creatures in our deck (and the ability to draw a ton of cards with Panharmonicon), so even if our opponent does have basic lands to find, our deck is better suited to take advantage of the extra mana