A method, proposed by Ryan Vigil in late 2017, based on tripod and sledgehammers. As a more intuitive method, it can be used to generate a good skeleton for FMC if steps are done loosely.
1. Build a cross. Very intuitive
2. Build F2L-1. This step can be done as the first step, using blockbuilding
3. Finish tripod. This step is done intuitively.
4. Place the remaining three edges using up to 2 sledgehammer algorithms. If parity occurs, use a J-perm to swap the two edges
5. Finish the remaining corners using either hexafusion or one of the 50 algorithms.
There are 4 possible types of cases that can be encountered while solving corners using the Sledgehog method. The first and most straightforward case method is where one corner is solved, and the other three are cycled. Most of this alg set is Last Three Corners or L3C (this set contains 24 algorithms including the pure corner twists and A-perms, but the pure alg set, the algs that both orient and permute, has 16). The other subset is a called Tripod Corners, and has 10 algorithms. (Not including pure corner twists)
The next type of case is one where all the corners are placed, but some are rotated. For this case you may just use beginners corners or use advanced algorithms.
The 3rd type of case is where no corner is in the right place. this alg set has 27 algorithms, but you may just use a triple sledgehammer to reduce it to the 2nd type of case. Not all of these algs have been generated.
The final type of case is where one corner is placed, but it is rotated. For this step you use a combination of (R' D' R D) (or a sort of warped sexy move) and U to both orient and permute the remaining corners. This process is called hexafusion because if (R' D' R D) is done 6 times, the cube will return to a solved state. If the U and U' moves are placed correctly, you can solve all the corners with the six "sexy moves". Hexafusion can be difficult to wrap your head around, and can only really be learned by practice.
Scramble: R' U L R2 F L' D' L2 B F L' U' F2 U2 R2 L2 U D2 L2 U'
Cross: x' D' L' D' U' R D' F B2
F2L-1: R U2 R' U' B' U' B U2 L' U' L2 F' L' F R' U2 R2 U R'
Tripod: y U' R U' R' F' U L' U' L F
Remaining edges: F R' F' R
Parity: R U2 R' U' R U2 L' U R' U' L
Hexafusion: (first corner) (R' D' R D) (fixing later problems) U' 2(D' R' D R) (second corner) U2 3(R' D' R D) (last two corners) U2 2(D' R' D R)
This method has potential for blockbuilding, adding freedom into the solve. A lucky scramble can get you nice blocks, and therefore quicker solves. All of the 3 corner algs are 12 moves or less, therefore being very fast to learn. In addition, during the sledgehammer stage, additional sledgehammers can be used to force a corner in, giving you a better corner case.
When you are using this method, lookahead is very difficult. It is very hard with a quick glance to tell the difference between a double corner swap and a hexafusion case, not to mention recognizing the corner swap cases.
Also, there are more rotations with this method, as corners can position themselves on any of three axes for a case.
Hexafusion has a high move count (upwards of 25 moves), so this step is not useful to FMC.
This method was developed independently of Ryan Heise's Tripod method, and is similar only in the construction of tripod. But even in that, Heise's method was developed for blockbuilding, and Vigil's sledgehog was designed with F2L in mind. However, these methods could be mixed in matched to cater to each scramble.
It can also be compared to CFOP, because both rely on F2L, but sledgehog leaves a slot to work with.
Sledgehog also has a subset in common with Anthony Snyder's method, as the last three corner subset is used in both.