Arsthbt

I'm trying to create a customized tcolorbox with some TikZ code in the overlay option.

But it works only the first time I use my new box. What am I doing wrong?

documentclassbook
usepackagetikzlings
usepackagemwe

usepackage[most]tcolorbox

newtcolorboxmybox[1][]%
 enhanced,
 before skip=30ex,
 after skip=10ex,
 colback=yellow, 
 frame hidden,% from https://tex.stackexchange.com/a/247509/101651
 % from https://tex.stackexchange.com/a/431760/101651:
 overlay=%
 beginscope
 clip (frame.north west) -- (frame.north east) -- ++(0,+10ex) -- 
 ++(-linewidth,0) -- cycle;
 marmot[xshift=.5linewidth]
 endscope
 beginscope
 clip (frame.south west) -- (frame.south east) -- ++(0,-10ex) -- 
 ++(-linewidth,0) -- cycle;
 marmot[xshift=.5linewidth, yshift=-tcbtextheight-2ex]
 endscope
 

begindocument
 beginmybox
 We love TiemphkZlings!
 endmybox
 beginmybox
 blindtext
 endmybox
enddocument

Oh no! No marmot on the second box! This has to be rectified! (As mentioned by @samcarter, the marmot got clipped away. But one can shift her or him back to visible region.)

documentclassbook
usepackagetikzlings
usepackagemwe

usepackage[most]tcolorbox

newtcolorboxmybox[1][]%
 enhanced,
 before skip=30ex,
 after skip=10ex,
 colback=yellow, 
 frame hidden,% from https://tex.stackexchange.com/a/247509/101651
 % from https://tex.stackexchange.com/a/431760/101651:
 overlay=%
 beginscope
 clip (frame.north west) -- (frame.north east) -- ++(0,+10ex) -- 
 ++(-linewidth,0) -- cycle;
 marmot[shift=([yshift=-7ex]frame.north),whiskers,teeth]
 endscope
 beginscope
 clip (frame.south west) -- (frame.south east) -- ++(0,-10ex) -- 
 ++(-linewidth,0) -- cycle;
 marmot[shift=([yshift=-4ex]frame.south),whiskers,teeth]
 endscope
 

begindocument
 beginmybox
 We love TiemphkZlings!
 endmybox
 beginmybox
 blindtext
 endmybox
enddocument

Some other tikzlings joined the party.

documentclassbook
usepackagetikzlings
usepackagemwe

usepackage[most]tcolorbox

newtcolorboxmybox[1][]%
 enhanced,
 before skip=30ex,
 after skip=10ex,
 colback=yellow, 
 frame hidden,% from https://tex.stackexchange.com/a/247509/101651
 % from https://tex.stackexchange.com/a/431760/101651:
 overlay=%
 beginscope
 clip (frame.north west) -- (frame.north east) -- ++(0,+10ex) -- 
 ++(-linewidth,0) -- cycle;
 marmot[shift=([yshift=-7ex]frame.north),whiskers,teeth]
 koala[shift=([yshift=-7ex,xshift=-5em]frame.north)]
 mouse[shift=([yshift=-7ex,xshift=5em]frame.north)]
 endscope
 beginscope
 clip (frame.south west) -- (frame.south east) -- ++(0,-10ex) -- 
 ++(-linewidth,0) -- cycle;
 marmot[shift=([yshift=-4ex]frame.south),whiskers,teeth]
 koala[shift=([yshift=-4ex,xshift=-5em]frame.south)]
 mouse[shift=([yshift=-4ex,xshift=5em]frame.south)]
 endscope
 

begindocument
 beginmybox
 We love TiemphkZlings!
 endmybox
 beginmybox
 blindtext
 endmybox
enddocument

And a cheesebox tends to attract mice (with important input by @samcarter in the chat).

documentclassbook
usepackagetikzlings
usepackagemwe

usepackage[most]tcolorbox

newtcolorboxmousebox[1][]%
 enhanced,
 before skip=30ex,
 after skip=10ex,
 underlay=%
 begintcbclipinterior
 fill [yellow]
 (interior.south west) rectangle (interior.north east);
 path let p1=($(interior.north east)-(interior.south west)$)
 in [/utils/exec=pgfmathtruncatemacroNX1+x1*1pt/3cm
 pgfmathtruncatemacroNY1+y1*1pt/2cmxdefNXNX
 xdefNYNY];
 foreach X in 1,...,NX
 foreach Y in 1,...,NY
 foreach x/y/r in 0.4/0.6/0.3, 
 0.5/1.3/0.2,%
 1.5/0.5/0.4,%
 1.5/0.5/0.4,% 
 2.1/1.5/0.3,%
 2.5/0.8/0.2,% 
 3.3/1.1/0.3
 shade[ball color=yellow!80!orange,opacity=0.2] 
 (x+(X-1)*3,y+(Y-1)*2) circle (r);
 
 endtcbclipinterior,
 ,
 %colback=yellow, 
 frame hidden,% from https://tex.stackexchange.com/a/247509/101651
 % from https://tex.stackexchange.com/a/431760/101651:
 overlay=%
 beginscope
 foreach Y in -5,0,5
 beginscope[shift=([yshift=-9ex,xshift=Y em]frame.north)]
 path[fill=gray!50]
 (0.5, 1.8) .. controls (0.5, 1.58) and (0.2, 1.25) .. (0, 1.16) .. controls (-0.2, 1.25) and (-0.5, 1.58) .. (-0.5, 1.8) .. controls (-0.34, 2.3) and (0.34, 2.3) .. (0.5, 1.8) -- cycle;
 path[fill=gray!50!black] (0, 1.248) circle (0.09);
 foreach X in 10,20,33%
 fill[gray!50!black] (0,1.2) + (X:0.08) to[out=X,in=180-X] ++(X-20:0.3) --++(0,0.01) to[out=180-X,in=X] cycle (0,1.2) + (180-X:0.08) to[out=180-X,in=X] ++(200-X:0.3) --++(0,0.01) to[out=X,in=180-X] cycle;
 
 endscope 
 
 clip (frame.north west) -- (frame.north east) -- ++(0,+10ex) -- 
 ++(-linewidth,0) -- cycle;
 foreach Y in -5,0,5
 mouse[shift=([yshift=-9ex,xshift=Y em]frame.north)]
 endscope
 beginscope
 clip (frame.south west) -- (frame.south east) -- ++(0,-10ex) -- 
 ++(-linewidth,0) -- cycle;
 foreach X in -5,0,5
 
 mouse[shift=([yshift=-4ex,xshift=X em]frame.south)]
 endscope
 

begindocument
 beginmousebox
 We love cheese!
 endmousebox
 beginmousebox
 blindtext
 endmousebox
enddocument