A common play call in the Seahawks' offense is the now-famous "green right spider two Y banana" and the close variation "green right strong spider three Y banana." It could also even be modified to sound like, "Green left strong slot spider three Y banana." There are dozens of other variations of this play in which slight changes in vocabulary determine the alignment, blocking scheme and routes run by the receivers. Definitions for each of these terms and how they influence alignment and assignment have been explained in depth over at HogsHaven, so if anyone wants to take a deeper look click here.
Basically, the play is designed to be a play-action pass in which the fullback is the primary receiver on the play. The FB first fakes like he is going to lead block before sneaking out into the flat. The secondary receiver is the TE who is running a "banana" route, which is why "Y banana" is in the play call. The tertiary receiver is often a WR or TE that is on a crossing route but this play is designed to be a quick hitting play so that player rarely gets the ball.
Here is a GIF of the Seahawks running it against Miami for a TD.
This play was run on 2nd and goal from Miami's 4 yard line. The Seahawks came out in "21" personnel, which usually signifies a run play with Michael Robinson as the lead blocker. Miami sent EIGHT defenders in an all-out blitz to stifle a Seahawks' rushing attempt but by doing so were left susceptible to the play-action pass. Robinson was wide open in the flat and since he was the primary receiver on this play, Russell Wilson was able to get him the ball immediately for a TD.
Furthermore, the Seahawks also run variations of this play from many different personnel packages. Here is an example of the Seahawks running this play out of "22" personnel against the Rams for a TD.
This play was run on 2nd and 3 from the Rams' 11 yard line. The Seahawks came out in "22" personnel which is a heavy run set. The Rams dialed up a run blitz and sent seven defenders which left Robinson wide open in the flat for a TD. Robinson, Sidney Rice and Anthony McCoy ran the same routes as the first example against Miami but the differences in the play were that it was run out of "22" personnel instead of "21" personnel and there was no receiver running a crossing route as a 3rd option.
Additionally, the Seahawks also make slight changes to the route combinations of this play but still utilize the same principles in order to maintain the sight adjustments that make the read progressions the same for the QB.
In the following example, the Seahawks are in "21" personnel and are lined up in an I-formation before motioning to a shotgun with split-backs formation. They run a play-action pass with Robinson as the primary receiver in the flat, Golden Tate as the secondary receiver on comeback route and Zach Miller as the tertiary receiver on a crossing route.
From a formation and route running standpoint, this play looks different than the previous examples. However, where Wilson has to look to make his progressions are very similar - his first look is to the receiver that is flat to the line of scrimmage, his second look is to the receiver that is 15 yards downfield between the numbers and the sideline, and his third look is to the receiver that is running the crossing route. By running more or less the same play but from an entirely different look, the Seahawks were able to disguise their intentions, and hit the Rams for a 19 yard gain.
Lastly, if you want to watch the professionals discuss this play, watch the clip below of Jon Gruden and Andrew Luck talking about the nuances of the many variations of this play at Gruden's 2012 QB camp on ESPN.
Big up to Danny for the gifs!