Cacophodon provides a nice crossover with the red pingers and both play well with mini-wildfire style effects that benefit from big mana, with X-spells that distribute damage (Rolling Thunder) becoming possibly very powerful with the other enrage creatures
Its rate of three mana for a 1/4 creature isnt the best, however, so there are definitely stronger mounts you could work with
Mind Twist was replaced by Mind Warp, which was a similar card, but cost more to cast
Obviously you are mostly playing cards like this to trigger prowess, fuel delve and delirium all while thinning the deck
The Beta and Unlimited versions of Time Walk cards are slightly more accessible than the others, but they're still in demand and, as with most collectibles, their prices vary according to the condition of the cards
But the long and short of it is a lhurgoyf is a made-up thing on which artists have been putting their spin for decades