Modern Dubious Deck.

After reading about Geological Appraiser's interaction with clone effects, I found myself wondering if that kind of thing could be made to work in other formats. Eventually I found myself thinking about Trumpeting Carnosaur. Hard-casting the Carnosaur is obviously not practical, but there are ways to cheat it into play like Dubious Outcome and, unlike the appraiser, the discover ability on carnosaur triggers even if it has not been cast. At CMC 4, dubious challenge can be cast off of Beseech the Mirror. Outcome does have some other limitations that need to be worked around - one is that the opponent will get one of the creatures, and another is that it only sees the top 10 cards of the library.

Through a circuitous route, it led me to wonder about something like...

4 Beseech The Mirror
4 Dubious Challenge
4 Trumpeting Carnosaur
4 Capricious Hellraiser
4 Etali, Primal Conqueror
4 Phyrexian Metamorph
4 Repudiate//Replicate
4 Saheeli Rai
2 Time Warp

4 Valgavoth's Lair
4 Glasspool Mimic//Glasspool Shore
4 Darkmoss Bridge
1 Opulent Palace
1 Xander's Lounge
1 Zagoth Triome
4 Overgrown Tomb
2 Swamp
1 Forest
1 Island
1 Mountain
4 Verdant Catacombs

in modern.

The chance to hit at least one of the Carnosaur, Hellraiser, or Etali on a Dubious Challege is around 91% and the chance to hit a second one of them, or a clone provided one has already been found is around 96%. As alternatives to Carnosaur, Etali starts a similar 'free cast' chain, and Hellraiser's effect can recast dubious challenge from the graveyard. (Hellraiser does not target, so it can cast the same dubious challenge that was used to put it into play.) Hellraiser and Etali are both a bit less than ideal, but I'm not sure what the alternatives are.

There is some risk of flipping Beseech off the top without having any bargain fodder. To help with that there are some token-producing copy effects like Repudiate//Replicate and Saheeli Rai

The idea is pretty simple from there: Chain a bunch of bodies into Time Warp and swing for the win on the extra turn.

This is pretty bad since it goes off slowly (turn 4 at best) and can require the graveyard to go off (due to Carnosaur), has very limited interaction ability on early turns, a significant fizzle rate, is vulnerable to counters, and the mana base is trying to do too much. A combo finish like this is also probably only fun once in casual contexts.