'Blunderbirds'.
Lammert Ditsel is a Dutch artist, who made comics during the late 1960 and early 1970s. Born in Alkmaar, he was living in Zaandam when he was active in the comics field. His 'Thunderbirds' parody 'Blunderbirds' (1967-1968) was published in the alternative monthly Knijp by publisher Triton. Another creation by Ditsel was 'Mannetje Wap', which presumably remained unpublished. He works as an illustrator with the quarterly magazine Shamrock of the Irish Wolfhound Club.