how merges go wrong??

still under juxtaposition. how did merges go wrong? mr radzi asked us to think of combination of two animals that if we combine them, they cannot survive..and i was thinking this

i was thinking that an animal of head of lion and a body of fish ( if you can see it is nemo!) could they survive??

but then mr radzi showed us this
erk? yea obviously this kinda animal cannot survive even a minute..