He is at his best in decks wanting to abuse graveyard effects, usually with green
Depopulate [Less than $1] Rare is the day where a four-mana boardwipe sells for under $1
The huge upside of this card is the ability mixed with first strike: The difference between the first strike damage phase and the regular damage phase allows you to hit with the reanimated creature immediately
Ojer Axonil, Deepest Might can wildly increase the damage it deals, turning it into an opponent-only board wipe
You can play a lot of the other frogs in the game, and surveilling is another way to put cards in the graveyard for Grolnok, the Omnivore to exile with its croak counters
If you aren't familiar with Magic (which is entirely reasonable given that we cover multiple card games on the site and there will be readers that don't particular about some of the games we cover), then the big deal with this card is the fact for 10 years, the ability simply couldn't be utilized under any circumstance at all