Tentacles is a skill taken by very strong players with Mutation access. The ability to prevent weak but agile opponents from moving is very useful.
Thick Skull has changed in the way it works gaining a very small boost in performance at the same time. Now also a Strength skill who would select it?
Wrestle is new in LRB5 and probably has the most impact of all the new skills. Read this for information on when to take Wrestle vs Block.