So, right now you have a team consisting of:
Excadrill and Krookodile are both ground types, but their second type differ.
Excadrill who has a second type of steel and krookodile who has a second type of dark, both fall under your bisharp's types. So, here's what you can do. You choose:
Excadrill -
- a great strong Pokemon who excels in hp and defense ; where krookodile not as much.
- excadrill can't bear too use any of his abilities, unless a sandstorm is created (I suggest you learn that move), unless you unlock its hidden ability.
- can evolve at a quicker level than krookodile
- has many more resistances and much less weaknesses than krookodile. Also, immune to electric and poison.
Krookodile -
- another great strong Pokemon who has higher iv's in defense, sp. attack, sp. defense, and speed than excadrill
- also, krookodile can learn many more moves than excadrill and in various types too.
- krookodile has a higher ev total than excadrill by 11.
- krookodile abilities can work against any Pokemon, plus they're much better than excadrill's
- krookodile may evolve at a higher level than excadrill, but this is because the remaining exp. is used to boost krookodile's stats. So, in appearance at the same level as excadrill, krookodile seems stronger.
So, by looking at these advantages and disadvantages, I highly recommend you choose Krookodile over Excadrill - not only because I like him better - but he appears more superior than excadrill.