We will need to include our image files in [gfx/pics.asm](../blob/master/gfx/pics.asm). However, with this method they can be stored in any bank so long as each pokemon's front and back sprite stay together in the same bank. We will create a new section called `Pics 7` for our new pokemon.

```diff
...
ChannelerPic::     INCBIN "gfx/trainers/channeler.pic"
AgathaPic::        INCBIN "gfx/trainers/agatha.pic"
LancePic::         INCBIN "gfx/trainers/lance.pic"
+
+SECTION "Pics 7", ROMX
+
+CrobatPicFront::  INCBIN "gfx/pokemon/front/crobat.pic"
+CrobatPicBack::   INCBIN "gfx/pokemon/back/crobatb.pic"
```

This method does assume that the pics for fossil kabutops, fossil aerodactyl, and ghost are all included in the same back, so we will move them to `Pics 7` as well.

```diff
...
BeedrillPicBack::     INCBIN "gfx/pokemon/back/beedrillb.pic"

-FossilKabutopsPic::   INCBIN "gfx/pokemon/front/fossilkabutops.pic"


SECTION "Pics 4", ROMX
...

...
CharizardPicBack::     INCBIN "gfx/pokemon/back/charizardb.pic"
-FossilAerodactylPic::  INCBIN "gfx/pokemon/front/fossilaerodactyl.pic"
-GhostPic::             INCBIN "gfx/battle/ghost.pic"
OddishPicFront::       INCBIN "gfx/pokemon/front/oddish.pic"
...

...
SECTION "Pics 7", ROMX

CrobatPicFront::  INCBIN "gfx/pokemon/front/crobat.pic"
CrobatPicBack::   INCBIN "gfx/pokemon/back/crobatb.pic"

+FossilKabutopsPic::   INCBIN "gfx/pokemon/front/fossilkabutops.pic"
+FossilAerodactylPic::  INCBIN "gfx/pokemon/front/fossilaerodactyl.pic"
+GhostPic::             INCBIN "gfx/battle/ghost.pic"
```

Next we must change `UncompressMonSprite` in [home/pics.asm](../blob/master/home/pics.asm) to work with this new method. 

```diff
UncompressMonSprite::
	ld bc, wMonHeader
	add hl, bc
	ld a, [hli]
	ld [wSpriteInputPtr], a    ; fetch sprite input pointer
	ld a, [hl]
	ld [wSpriteInputPtr+1], a
-; define (by index number) the bank that a pokemon's image is in
-; index = MEW:             bank $1
-; index = FOSSIL_KABUTOPS: bank $B
-;       index < $1F:       bank $9 ("Pics 1")
-; $1F ≤ index < $4A:       bank $A ("Pics 2")
-; $4A ≤ index < $74:       bank $B ("Pics 3")
-; $74 ≤ index < $99:       bank $C ("Pics 4")
-; $99 ≤ index:             bank $D ("Pics 5")
	ld a, [wcf91]
-	ld b, a
-	cp MEW
-	ld a, BANK(MewPicFront)
-	jr z, .GotBank
-	ld a, b
	cp FOSSIL_KABUTOPS
+	jr z, .RecallBank
+	cp FOSSIL_AERODACTYL
+	jr z, .RecallBank
+	cp MON_GHOST
+	jr z, .RecallBank
+	ld a, [wMonHPicBank]
+	jr .GotBank
+.RecallBank
	ld a, BANK(FossilKabutopsPic)
-	jr z, .GotBank
-	ld a, b
-	cp TANGELA + 1
-	ld a, BANK("Pics 1")
-	jr c, .GotBank
-	ld a, b
-	cp MOLTRES + 1
-	ld a, BANK("Pics 2")
-	jr c, .GotBank
-	ld a, b
-	cp BEEDRILL + 2
-	ld a, BANK("Pics 3")
-	jr c, .GotBank
-	ld a, b
-	cp STARMIE + 1
-	ld a, BANK("Pics 4")
-	jr c, .GotBank
-	ld a, BANK("Pics 5")
-
.GotBank
	jp UncompressSpriteData
...
```

In case that's hard to read, here's what the function should look like when you're done:

```
UncompressMonSprite::
	ld bc, wMonHeader
	add hl, bc
	ld a, [hli]
	ld [wSpriteInputPtr], a    ; fetch sprite input pointer
	ld a, [hl]
	ld [wSpriteInputPtr+1], a
	ld a, [wcf91] ; XXX name for this ram location
	cp FOSSIL_KABUTOPS
	jr z, .RecallBank
	cp FOSSIL_AERODACTYL
	jr z, .RecallBank
	cp MON_GHOST
	jr z, .RecallBank
	ld a, [wMonHPicBank]
	jr .GotBank
.RecallBank
	ld a, BANK(FossilKabutopsPic)
.GotBank
	jp UncompressSpriteData
...
```

We will now need to add `wMonHPicBank` into (wram.asm)[../blob/master/wram.asm] just before the end of the mon header.

```diff
...
wMonHeader::
; In the ROM base stats data structure, this is the dex number, but it is
; overwritten with the internal index number after the header is copied to WRAM.
wMonHIndex:: db
wMonHBaseStats::
wMonHBaseHP:: db
wMonHBaseAttack:: db
wMonHBaseDefense:: db
wMonHBaseSpeed:: db
wMonHBaseSpecial:: db
wMonHTypes::
wMonHType1:: db
wMonHType2:: db
wMonHCatchRate:: db
wMonHBaseEXP:: db
wMonHSpriteDim:: db
wMonHFrontSprite:: dw
wMonHBackSprite:: dw
wMonHMoves:: ds NUM_MOVES
wMonHGrowthRate:: db
wMonHLearnset:: flag_array NUM_TMS + NUM_HMS
-	ds 1
+wMonHPicBank:: db
wMonHeaderEnd::
...
```

Finally, we need to update each pokemon's base stat data with the bank of their picture. You could do this by individually changing each file, but don't. We can easily do this automatically by using [sed](https://www.gnu.org/software/sed/manual/sed.html). Simply run the following code in your terminal (note for Cygwin users: by default, paste is set to `shift+ins` instead of the `ctrl+v` you may be used to):

```
for f in data/pokemon/base_stats/*.asm; do
    cat $f \
    | tr '\n' '\v' \
    | sed -E 's/dw (\w+), (\w+)(.+)(..)db [%01]+ ; padding/dw \1, \2\3\4db BANK(\1)\4assert BANK(\1) == BANK(\2)/g' \
    | tr '\v' '\n' \
    > $f.tmp;
    mv -f $f.tmp $f;
done
```

and all your base stat files should now be properly updated.

 ```diff
	db DEX_CROBAT ; pokedex id

	db  85,  90,  80,  130,  80
	;   hp  atk  def  spd  spc

	db POISON, FLYING ; type
	db 90 ; catch rate
	db 241 ; base exp

	INCBIN "gfx/pokemon/front/crobat.pic", 0, 1 ; sprite dimensions
	dw CrobatPicFront, CrobatPicBack

	db LEECH_LIFE, SCREECH, BITE, SCREECH ; level 1 learnset
	db GROWTH_MEDIUM_FAST ; growth rate

	; tm/hm learnset
	tmhm RAZOR_WIND,   WHIRLWIND,    TOXIC,        TAKE_DOWN,    DOUBLE_EDGE,  \
	     HYPER_BEAM,   RAGE,         MEGA_DRAIN,   MIMIC,        DOUBLE_TEAM,  \
	     BIDE,         SWIFT,        REST,         SUBSTITUTE,   FLY
	; end

-	db 0 ; padding
+	db BANK(CrobatPicFront)
+	assert BANK(CrobatPicFront) == BANK(CrobatPicBack)
```