Strange, really strange.

header
lorom

org $00F349
db $03

org $00F37A
NOP #3

org $00F377
autoclean	JSL MessageCheck

freecode

db "STAR"                        ;\
dw End-MessageCheck-$01           ; |RATS tag
dw End-MessageCheck-$01^$FFFF     ;/

MessageCheck:
LDA $1F3B
BEQ MessageShow

CustomYoshi:
LDA $1422
CMP #$02
BEQ DoStuff
RTL

DoStuff:
STZ $1420
STZ $1422
LDA #$01
STA $18E4
LDA #$0D
STA $16E1
DEC $0DBE
DEC $1422
RTL

MessageShow:
LDA #$01
STA $1F3B
LDA #$03
STA $1426
BRA CustomYoshi
End: